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EDWARD   G.   JANEWAY 

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ON    THE 

PHYSIOLOGY  OF  THE  SEMICIRCULAR 

CANALS  AND   THEIR   RELATION 

TO   SEASICKNESS 


ON    THE 

PHYSIOLOGY  OF  THE  SEMI 

CIRCULAR    CANALS    AND 

THEIR  RELATION  TO 

SEASICKNESS 


BY 

JOSEPH  BYRNE,  A.M.,  M.D.,  LL.B. 


NEW    YORK 
J.    T.    DOUGHERTY 


LONDON 
H.    K.    LEWIS 


MDCCCCXII 


Copyright,  1912,  by 

JOSEPH    BYRNE 

New  York 

Entered  at  Stationers'  Hall,  London,  1912 


All  Rights  reserved 


Printed  in  the  United  States  of  America 


The  Book  Composition  Company, 
155  East  Twenty-third  Street,  New  York 


TO 
DAVID    FERRIER 

A  PIONEER  IN  THE  PHYSIOLOGY  OF  THE  NERVOUS 
SYSTEM,  WHOSE  CAREFUL  EXPERIMENTS,  ACCURATE 
OBSERVATIONS,  AND  SOUND  DEDUCTIONS  RENDER 
HIS  WORK  A  GUIDE  AND  INSPIRATION  FOR  STUDENTS 
OF    GENERATIONS    TO    COME 


PREFACE 


Six  years  ago  the  author  undertook  to  write  an  arti- 
cle on  the  etiology  of  seasickness.  Not  satisfied  with  a 
mere  expression  of  views  without  appeal  to  experimental 
fact,  and  believing  that  the  semicircular  canals  were  in 
some  way  involved  in  the  causation  of  the  malady,  he 
undertook  of  his  own  suggestion  and  forethought,  a  series 
of  experiments  using  rotations,  aural  irrigations,  stimula- 
tion of  the  retina  by  strong  light,  galvanism  applied  to 
the  mastoid  areas,  etc.,  to  determine  whether  by  such 
means  phenomena  resembling  those  of  seasickness  could 
be  experimentally  reproduced.  The  results  of  his  earliest 
experiments  fulfilled  his  expectations  to  such  an  extent, 
that  he  proceeded  to  a  thorough  study  of  the  semicircular 
canals,  as  affected  by  rotations,  aural  irrigations  and  gal- 
vanism. 

The  phenomena  of  nystagmus  and  the  displacements 
of  the  head  that  occur  in  rotations,  aural  irrigations,  and 
galvanism  applied  to  the  mastoid  areas,  were  observed  by 
him  independently  and  the  mechanisms  involved  in  their 
production  studied  and  worked  out  before  he  had  any 
information  of  the  work  done  by  Barany,  Neumann  and 
others.  He  makes  therefore,  no  pretensions  for  this  part 
of  his  work  on  the  score  of  priority  in  time,  but  submits 
it  to  the  profession  in  the  hope  that  the  work  will  speak 
for  itself. 

Armed  with  the  knowledge  and  experience  gained  from 
a  thorough  study  of  the  sickness  produced  by  rotations, 

v 


vi  PREFACE 

aural  irrigations,  etc.,  he  next  proceeded  to  the  experi- 
mental study  of  seasickness,  the  results  of  which  are  de- 
tailed in  Part  III. 

Although  numerous  volumes  were  consulted  the  author 
owes  special  acknowledgment  to  the  works  of  Ferrier, 
Sherrington,  Piersol,  Risien-Russell,  and  Ewald.  The 
description  of  the  labyrinth  and  of  the  eighth  nerve  is 
taken  mainly  from  Piersol' s  Human  Anatomy. 

The  author  wishes  to  thank  Dr.  Bailey  and  Messrs. 
William  Wood  &  Co.  for  permission  to  reproduce  three 
figures  from  Dr.  Bailey's  work  on  Histology.  He  also 
wishes  to  thank  his  friend  Mr.  Hugh  J.  Smith  for  the 
patience  and  fortitude  with  which  he  submitted  to  the 
various  tests,  as  well  as  for  the  intelligent  assistance 
given  in  describing  the  subjective  phenomena. 

The  author  has  always  been  an  acute  sufferer  from  sea- 
sickness, and  the  time  and  labour  devoted  to  these  inves- 
tigations, which  were  conducted  in  private,  he  considers 
well  spent  if  his  efforts  tend  to  a  better  understanding  of 
this  distressing  malady,  with  consequent  alleviation  of 
unspeakable  human  misery. 

J.  Byrne. 

29  West  61st  Street,  New  YorK  City, 
January,  1912. 


CONTENTS 


PART  I 

GENERAL   ANATOMICAL   AND   PHYSIOLOGICAL 
CONSIDERATIONS 

CHAPTER  PAGE 

I.   Anatomy  of  the  Labyrinth 3 

XL   The  Eighth  Nerve .    12 

III.  The  Remaining  Cranial  Nerves     ....    22 

IV.  Blood-supply  of  the  Labyrinth  and  of  the 

Cranial  Nuclei 37 

V.   Synopsis  op  Anatomical  Connections       .      .    40 

VI.   The    Sympathetic    or    Autonomic    Nervous 

System 98 

VII.   The   Paths    Involved    in    Pupillary    Move- 
ments     105 

VIII.   Further  Anatomical  and  Physiological  Con- 
siderations       114 


PART  II 

PHYSIOLOGY   OF   THE   SEMICIRCULAR   CANALS 

IX.  Physiology  of  the  Semicircular  Canals 
FROM  THE  Standpoint  of  Animal  Experi- 
mentation   125 

X.   The  Effects  of  Passive  Rotation       .     .      .  130 

vii 


viii  CONTENTS 

CHAPTER  PAGE 

XL   The  Effects  of  Rotation  upon  the  Digestive 

Apparatus 164 

XII.  The  Effect  of  Drugs  and  Other  Measures 
UPON  Derangements  of  the  Alimentary 
System  Caused  by  Rotation  Sickness  .      .  183 

XIII.  The  Effect  of  Rotation  upon  Equilibrium  192 

XIV.  The  Effects  of  Rotation  upon  the  Eyes     .  198 

XV.   The  General  Effects  of  Aural  Irrigations  207 

XVI.  The  Effects  of  Aural  Irrigations  upon  the 

Digestive  Apparatus 233 

XVII.   The  Effects  of  Aural  Irrigations  upon  the 

Eyes 250 

XVIII.   The  Effects  of  the  Galvanic  Current  upon 

the  Semicircular  Canals 268 

XIX.  How  Rotations,  Aural  Irrigations  and  Gal- 
vanism Affect  the  Labyrinthine  Recep- 
tors and  the  Related  Effectors  .      .      .273 

XX.   Mechanism  of  the  Nystagmus  of  Rotations, 

Aural  Irrigations  and  Galvanism  .      .      .  288 

XXI.  Relations  of  the  Semicircular  Canals  to 
the  Oculo-Motor  Nuclei  and  their  Bear- 
ing UPON  THE  Results  of  Certain  Experi- 
ments        306 

XXIL   On  Ocular  Movements  and  Nystagmus    .      .  315 

XXIII.    On  the  Occurrence  of  Nystagmus     .      .      .331 


PART  III 

SEASICKNESS 

XXIV.   Studies  in  Seasickness 339 

XXV.    Further   Studies    in  Seasickness  During  a 

Transatlantic  Trip 345 

XXVI.   Studies  in  Seasickness  (Continued)   .      .      .357 


CONTENTS  ix 

PAGE 

CHAPTER 

XXVII.   Studies  in  Seasickness  (Continued)    .      .      .379 

XXVIII.    Studies  in  Seasickness  (Continued)   .      .      .384 

XXIX.   General  Conclusions  from   Studies  in  Sea- 
sickness.   Protocols 417 

XXX.   History  and  Literature  of  Seasickness       .  473 

XXXI.   Etiology  of  Seasickness 4S6 

XXXII.   Etiology  of  Seasickness  (Continued)      .      .  496 

XXXIII.  On  the  Occurrence  of  Seasickness   .      .      .508 

XXXIV.  The  Effects  of   Seasickness  and  Their  Re- 

lation TO  Diseased  Conditions  .      .      .      .512 

XXXV.   How    Recovery    from     Seasickness    Takes 

Place.    Outlines  of  Treatment      .      .      .518 


BIBLIOGRAPHY ^^7 

INDEX „      ...  537 


PART  I 

GENERAL  ANATOMICAL  AND  PHYSIOLOGI- 
CAL CONSIDERATIONS 


CHAPTER  I 

ANATOMY   OF  THE  LABYRINTH 

The  long  axis  of  the  internal  ear  measures  about  20 
mm,  and  corresponds  with  that  of  the  petrous  bone. 
The  cavity  of  the  bony  labyrinth  is  divided  into  an  ante- 
rior portion,  the  cochlea,  a  middle  portion,  the  vestibule, 
and  a  posterior  portion,  the  semicircular  canals.  The 
vestibule  is  an  irregularly  elliptical  cavity  measuring 
about  5  mm  from  before  backward,  the  same  from  above 
downward,  and  about  3 — 4  mm  from  without  inward. 
The  outer  wall  constitutes  that  part  of  the  inner  wall  of 
the  tympanic  cavity  in  which  the  oval  window  is  situated. 
The  medial  or  inner  wall  is  directed  toward  the  bottom  of 
the  internal  auditory  canal,  and  has  two  depressions  sepa- 
rated by  a  ridge — ^the  crista  vestibuli,  the  upper  pointed 
end  of  which  forms  the  pyramidalis  vestibuli.  The 
anterior,  the  smaller  of  these  depressions,  is  the  spherical 
recess  and  lodges  the  saccule.  In  the  lower  part  of  this 
fossa  a  number  of  perforations  (about  a  dozen)  mark  the 
macula  cribosa  media,  through  which  pass,  from  the  bot- 
tom of  the  internal  auditory  canal,  the  branches  of  the 
vestibular  nerve  to  the  saccule.  The  posterior,  larger 
depression,  is  the  elliptical  recess,  which  lodges  the  utricle. 
Behind  the  lower  part  of  the  spherical  recess  the  crista 
vestibuli  divides  into  two  limbs,  between  which  is  the 
recessus  cochlear  is,  which  lodges  the  beginning  of  the 
ductus  cochlearis,  and  is  pierced  by  a  number  of  small 
openings  for  passage  of  the  nerve  filaments  to  this  duct. 
The  openings  in  the  crista  vestibuli  and  the  elliptical 
recess  collectively  form  the  macula  cribrosa  superior,  and 
transmit  branches  of  the  vestibular  nerve  to  the  utricle 
and  to  the  ampullae  of  the  superior  and  horizontal  semi- 
circular canals.  Below  and  behind  the  recessus  ellipticus 
lies  a  groove,  the  fossa  sulciformis,  which  deepens  pos- 


4  SEMICIRCULAR  CANALB 

teriorly  into  a  ven^  small  canal — the  aqugeductus  vesti- 
buli,  and  runs  in  a  slightly  curved  course  to  the  posterior 
surface  of  the  petrous  bone,  where  it  ends  in  a  slitlike 
opening — the  apertura  externa  aqugeductus  vestibuli,  situ- 
ated between  the  internal  opening  of  the  internal  auditory- 
canal  and  the  groove  for  the  lateral  sinus.  The  canal 
transmit-s  the  ductus  endolymphaticus  and  a  small  vein. 
The  anterior  wall  of  the  vestibule  is  pierced  by  the  large 
opening  leading  into  the  scala  vestibuli  of  the  cochlea. 
Near  this  opening  is  seen  the  beginning  of  the  lamina 
spiralis  ossea,  which  lies  on  the  floor  of  the  vestibule  be- 
low the  oval  window.  Posteriorly  the  vestibule  communi- 
cates with  the  semicircular  canals  by  five  small  openings. 

The  semicircular  canals  are  three  small  bony  tubes,  of 
a  shape  indicated  by  their  name.  They  constitute  the 
posterior  division  of  the  bony  labyrinth.  The  direction 
of  each  canal  corresponds  roughly  with  one  of  the  funda- 
mental planes  of  the  body,  viz.,  the  superior  canal  corre- 
sponds with  the  coronal  or  frontal,  the  posterior  with  the 
sagittal,  and  the  horizontal  with  the  transverse.  The 
plane  of  their  direction  is  such  that  each  canal  is  at  right 
angles  to  the  direction  of  each  of  its  fellows.  At  one  end 
of  each  canal  there  is  a  dilated  portion — the  ampulla. 
The  superior  canal  lies  farthest  front,  and  in  nearly  a  ver- 
tical plane  at  right  angles  to  the  long  axis  of  the  petrous 
bone.  The  plane  of  the  posterior,  which  is  the  longest  of 
the  canals,  is  approximately  parallel  to  the  long  axis  of 
the  petrous  bone.  The  external  portion  of  the  horizontal 
semicircular  canal  forms  a  prominence  in  the  inner  wall 
of  the  middle  ear,  behind  the  facial  canal,  while  the 
upper  part  of  the  superior  semicircular  canal  produces  a 
conspicuous  elevation — the  eminentia  arcuata,  seen  on 
the  superior  surface  of  the  petrous  bone.  The  canals 
open  into  the  ]:)ost(3rior  part  of  the  vestibule  by  five  open- 
ings, the  undilated  ends  of  the  superior  and  posterior 
canals  uniting  U)  form  a  common  trunk,  the  crus  com- 
mune. The  iKjrizontal  canal  alone  has  two  distinct  open- 
ings into  the  vestibule.  Its  ampulla  is  at  its  outer  end, 
and  lir'H  at  the  iippnr  ))ait  of  the  v(?stibule,  above  the  oval 
window,  from  wliich  it  is  sf^mrated  by  a  groove  corre- 
sponding with  the  facial  canal. 

The  ampullary  end  of  the  posterior  canal  lies  on  the 


ANATOMY  5 

floor  of  the  vestibule,  near  the  opening  of  the  undilated 
end  of  the  horizontal  canal  and  that  of  the  canalis  com- 
munis. The  ampulla  of  the  superior  canal  lies  in  the 
vicinity  of  the  ampulla  of  the  horizontal  canal,  but  is 
situated  somewhat  mesial  to  it.  This  is  an  important 
relation  in  view  of  the  fact  that  stimuli  by  means  of  irri- 
gations in  the  external  auditory  canal,  or  by  means  of 
galvanism  over  the  mastoid  area,  usually  affect  the  am- 
pulla of  the  horizontal  canal  only;  but  if  thermic  irrita- 
tion be  long  continued,  or  if  there  be  structural  changes 
due  to  long-continued  disease  of  the  middle  ear,  pheno- 


AmjpuUas 


Ampulla 


The  Bony  Labyrinth. 

{From  "  Histology,"  by  Dr.  Bailey. 


X3.   (Heitzmann.) 

Wm.  Wood  &  Co.,  Publishers) 


mena  indicating  irritation  of  the  ampulla  of  the  superior 
canal  may  appear  simultaneously  with  those  from  irrita- 
tion of  the  ampulla  of  the  horizontal  canal,  or  may  even 
be  present  to  the  exclusion  of  the  latter.  In  the  wall  of 
the  ampulla  of  the  posterior  canal  a  number  of  small 
openings  constituting  the  macula  cribrosa  inferior  provide 
for  entrance  of  the  special  branch  of  the  vestibular  nerve, 
destined  for  this  canal.  Sappey  ^  states  that  the  superior 
canal  bends  somewhat  upon  itself,  so  that  the  anterior 
(external)  half  inclines  a  little  inward  {e7i  dedans),  and 
the  posterior  (internal)  half  inclines  a  little  outward  (e7i 
deJiors).  Poirier  and  Charpy^  follow  Sappey 's  descrip- 
tion, which  is  undoubtedly  accurate. 


6  SEMICIRCULAR   CANALS 

The  membranous  labyrinth  lies  within  the  bony  laby- 
rinth, and  resembles  it  in  general  form.  This  agreement 
is  least  marked  in  the  vestibule,  since  here  the  bony  cap- 
sule is  occupied  by  two  compartments  of  the  membranous 
sac — the  utricle  and  saccule.  The  membranous  labyrinth 
comprises : 

1.  The  utricle  and  saccule,  which,  with  the  ductus 
endolymphaticus,  lie  within  the  vestibule. 

2.  The  three  membranous,  semicircular  canals,  which 
lie  within  the  bony  canals. 

3.  The  membranous  cochlea  enclosed  within  the  bony 
cochlea. 

The  membranous  labyrinth  is  attached  especially  at 
certain  places  by  connective  tissue  to  the  inner  wall  of 
the  bony  capsule.  The  space  between  the  membranous 
and  bony  labyrinths — largest  in  the  scala  tympani  and 
scala  vestibuli  of  the  cochlea  and  in  the  vestibule — consti- 
tutes the  spatium  perilymphaticum,  and  contains  a  modi- 
fied lymphatic  fluid,  the  perilymph.  The  fluid  which 
fills  the  interior  of  the  membranous  labyrinth  is  called 
the  endol}mi23h,  and  can  pass  from  one  part  of  the  laby- 
rinth to  another,  although  the  saccule  and  utricle  are  only 
indirectly  connected  through  a  narrow  channel — the  duc- 
tus endolymphaticus.  The  utricle  occupies  the  recessus 
ellii:)ticus  in  the  uj^per  and  back  part  of  the  vestibule. 
Larger  than  the  saccule,  it  communicates  with  the  three 
membranous  semicircular  canals.  It  is  attached  to  the 
upper  and  inner  walls  of  the  vestibule  by  connective  tis- 
sue. It  extends  from  the  roof  of  the  vestibule  backward 
and  downward  to  the  opening  of  the  j^osterior  ampulla 
(5.5  to  G  mm). 

The  utricle  has  three  subdivisions,  the  uppermost  a 
blind  sac  (3  to  3.5  mm  in  length  and  breadth),  called  the 
recessus  utriculi,  whilst  the  two  lower  divisions  form  the 
utriculus  proprius,  which  measures  8  mm  by  L 5  to  2  mm. 
The  lower  part  of  the  utricle  proper  is  prolonged  into  the 
tube-shaped  sinus  posterior,  which  connects  the  ampulla 
of  posterior  canal  with  the  utricle. 

The  openings  of  the  semicircular  canals  into  the 
utricle  are  as  follows :  (a)  Into  the  recessus  utriculi :  the 
ampulhe  of  the  superior  and  horizontal  canals,  (b)  Into 
the  utriculus  proprius : 


ANATOMY  T 

1.  The  sinus  superior,  which  lies  within  the  crus  com- 
mune, and  receives  in  turn  the  non-ampullated  ends  of 
the  superior  and  posterior  canals. 

2.  The  non-ampullated  end  of  the  horizontal  canal. 

8.  The  ampulla  of  the  posterior  canal  through  the 
sinus  posterior. 

On  the  antero-lateral  wall  of  the  recessus  utriculi  is 
placed  the  macula  acustica  of  the  utricle,  whilst  from  its 
antero-mesial  wall  springs  the  canalis  utriculo-saccularis, 
the  small  canal  from  the  utricle  that  joins  a  still  smaller 
passage  from  the  saccule  to  form  the  ductus  endolym- 
phaticus. 

The  saccule  is  an  irregularly  oval  compartment,  about 
8  by  2  mm,  occupying  the  recessus  sphsericus  in  the 
lower  and  anterior  part  of  the  vestibule,  to  w^hich  it  is 
attached  by  connective  tissue.  It  is  somewhat  flattened 
laterally,  and  at  its  lower  end  gradually  narrows  into  a 
passage — the  canalis  reuniens,  which  connects  the  saccule 
with  the  ductus  cochlearis.  Its  upper  end  bulges  back- 
ward, forming  the  sinus  utricularis,  the  wall  of  which 
comes  in  contact  with  that  of  the  utricle.  The  small 
canal  that  helps  to  form  the  ductus  endolymphaticus 
springs  from  the  posterior  wall  of  the  saccule.  The  duc- 
tus endol}miphaticus  passes  through  the  aquseductus  ves- 
tibuli  to  end  in  a  blind  dilated  extremity,  the  saccus 
endol}Txiphaticus,  lying  between  the  layers  of  the  dura 
mater  below  the  opening  of  the  aqueduct.  Through  open- 
ings in  the  recessus  sphsericus  branches  of  the  vestibular 
nerve  enter  and  pass  to  the  macula  acustica  sacculi  on  the 
anterior  wall  of  the  saccule.  The  canalis  reuniens  is  the 
very  small  tube  passing  from  the  lower  part  of  the  saccule 
into  the  upper  wall  of  the  cochlear  duct,  near  the  caecum, 
as  its  blind  vestibular  end  is  called. 

The  membranous  semicircular  canals  (ductus  semi- 
circulares)  occupy  about  one-third  of  the  diameter  of  the 
osseous  canals,  and  correspond  with  them  in  number, 
name,  and  form.  They  are  closely  united  along  their 
convex  margins  with  the  bony  tubes,  whilst  the  opposite 
concave  margins  lie  free  in  the  perilymphatic  space,  being 
attached  only  by  irregular  vascular  connective-tissue 
bundles  (ligamenta  labyrinthi  canaliculorum) ,  which 
stretch  across  this  space.     Each  of  the  membranous  tubes 


8 


SEMICIRCULAR   CANALS 


has  an  ampulla,  which  is  relatively  much  larger  than  the 
osseous  ampulla,  being  three  times  the  size  of  the  rest  of 
the  tube.  The  part  of  the  ampulla  corresponding  to  the 
convexity  of  the  semicircular  canals  is  grooved  on  the 


Diagram  of  the  Perilymphatic  and  Endolymphatic  Spaces 
of  the  Inner  Ear.  (Testut.)  Endolymphatic  spaces  in  grey; 
perilymphatic  spaces  in  black.  1,  Utricle  ;  2,  saccule  ;  3,  semi- 
circular canals;  4,  cochlear  canal;  5,  endolymphatic  duct; 
6,  subdural  endolymphatic  sac;  7,  canalis  reuniens;  8,  scala 
tympani ;  9,  scala  vestibuli ;  10,  their  union  at  the  helicotrema; 
11,  aqueduct  of  the  vestibule;  12,  aqueduct  of  the  cochlea;  13, 
periosteum ;  14,  dura  mater ;  15,  stapes  in  fenestra  ovalis ;  16, 
fenestra  rotunda  and  secondary  tympanic  membrane. 

{From  "Histology,"  by  Dr.  Bailey.     Wm.  Wood  &  Co.,  Publishers) 


outer  surface  at  the  entrance  of  the  ampullary  nerves. 
On  the  corresponding  inner  surface  is  a  projection — the 
septum  transvorsum — which  practically  divides  this  space 
inUj  two  parts,  and  is  surmoimtod  by  the  crista  acustica, 
which  contains  the  ampullary  endings  of  the  vestibular 


ANATOMY  9 

nerves.     The  crescent-shaped  thickening  beyond  each  end 
of  the  crista  is  called  the  planum  semilunatum. 

Structure  of  the   Utricle^  Saccule^  and  Semicircular 

Canals. 

The  vestibule  and  the  bony  semicircular  canals  are 
lined  by  a  very  thin  periosteum,  composed  of  a  feltwork 
of  resistant  fibrous  tissue  containing  pigmented  connect- 
ive-tissue cells.  Endothelium  everj^where  lines  the  peri- 
lymphatic space  between  the  membranous  and  osseous 
canals,  covering  the  free  inner  surface  of  the  periosteum, 
the  fibrous  trabeculae,  and  the  outer  or  peril}Tnphatic  sur- 
face of  this  part  of  the  membranous  labyrinth.  The  walls 
of  the  utricle,  saccule,  and  membranous  semicircular 
canals  are  made  up  of  (a)  an  outer  fibrous  connective- 
tissue  lamella,  and  (b)  an  iimer  epithelial  lining,  the 
latter  consisting  throughout  the  greater  part,  of  its  extent  of 
a  single  layer  of  thin,  flattened,  polyhedi-al  cells.  Beneath 
the  epithelium,  in  the  region  of  the  maculae  and  cristae, 
is  (c)  a  thin,  almost  homogeneous,  hyaline  membrane 
with  few  cells.  This  middle  layer  presents,  in  places,  on 
its  inner  surface  small  papillary  elevations  covered  by 
epithelium.  On  the  concave  side  of  the  semicircular 
canals  is  a  strip — ^the  raphe — of  thickened  epithelium,  in 
which  the  cells  become  low,  cylindrical  in  type.  In  the 
plana  semilunata  the  cells  are  cylindrical  in  type.  Over 
the  regions  receiving  the  nerve  fibres — the  maculae  acus- 
ticse  and  the  cristae  acusticae — the  epithelium  undergoes  a 
marked  alteration,  changing  from  the  indifferent  covering 
cells  into  the  highly  specialized  neuro-epithelium. 

The  maculae  acusticae  are  about  3  mm  long  by  2  mm 
broad,  the  macula  of  the  saccule  being  a  little  narrower 
(1.5  to  1.6  mm)  than  that  of  the  utricle  (2  mm).  At 
the  margin  of  these  areas  the  cells  are  at  first  cuboidal, 
next  low  columnar,  and  then  they  abruptly  increase  in 
length  until  they  measure  from  0.30  to  0.3o  mm,  in  con- 
trast with  their  usual  height  of  from  .003  to  .004  mm. 
The  acoustic  area  includes  two  kinds  of  elements — the 
sustentacular  or  fibre  cells  and  the  hair  cells.  The  susten- 
tacular  cells  are  long,  rather  narrow,  irregularly  cylindri- 
cal elements,  and  extend  the  entire  thickness  of  the  epi- 


10  SEMICIRCULAR   CANALS 

thelial  layer,  resting  upon  a  well-developed  basement 
membrane  by  their  expanded  or  divided  basal  processes. 
At  a  variable  distance  from  the  base  they  present  a  swell- 
ing enclosing  an  oval  nucleus,  and  terminate  at  the  surface 
in  a  cuticular  zone.  The  cylindrical  hair  cells  are  broader 
but  shorter  than  the  sustentacular  cells,  and  reach  from 
the  free  surface  only  as  far  as  the  middle  of  the  epithelial 
layer,  where  each  cell  terminates  usually  in  a  rounded  or 
somewhat  swollen  end,  containing  a  spherical  nucleus. 
The  end  next  to  the  free  surface  exhibits  a  differentiation 
into  a  cuticular  zone,  similar  to  that  covering  the  inner 
ends  of  the  sustentacular  elements. 

From  the  free  border  of  each  hair  cell  a  stiff,  robust 
hair,  .020  to  .025  mm  long,  projects  into  the  endolymph. 
This,  however,  is  resolvable  into  a  number  of  aggluti- 
nated, finer  hairs  or  rods.  The  free  surface  of  the  neuro- 
epithelium  within  the  saccule  and  utricle  is  covered 
by  a  remarkable  structure,  the  so-called  otolithic  mem- 
brane. This  consists  of  a  gelatinous  membrane,  in  which 
are  imbedded  numberless  small,  crystalline  bodies,  the 
otoliths.  Between  it  and  the  cuticular  zone  is  a  space, 
about  .020  mm  in  width  and  filled  with  endolymph, 
through  which  the  hair  cells  pass  to  the  otolithic  mem- 
brane. The  otoliths  are  minute  crystals,  usually  hexa- 
gonal in  form,  with  slightly  rounded  angles,  and  from 
.009  to  .011  mm  in  length.  They  are  composed  of  cal- 
cium carbonate,  with  an  orgjinic  basis.  On  reaching  the 
macula  the  nerve  fibres  form  a  subepithelial  plexus,  from 
which  fine  bundles  of  fibres  pass  toward  the  free  surface. 
The  fibres  usually  lose  their  medullary  substance  in  pass- 
ing through  the  basement  membrane,  and  enter  the  epithe- 
lium as  naked  axis-cylinders.  Passing  between  the  sub- 
cuticular cells  to  about  the  middle  of  the  epithelium,  they 
break  up  into  fine  fibrilla),  which  embrace  the  deeper  ends 
of  the  hair  cells,  and  give  off  fine  threads  tliat  pass  as 
free  axis  cylinders  between  the  cells  to  higher  levels. 

The  crista  acustica  and  planum  soinilimatum  are  cov- 
ered with  neuro-epitheli urn,  similar  to  thatof  the  macula). 
The  hairs  of  the  hair  cells,  however,  are  longer  and  con- 
verge to,  and  are  imbedded  witliin,  a  peculiar  domelike 
structure  known  as  the  cupola,  regarded  by  some  anato- 
mists as  an  artefact  formed  by  coagulation  of  the  fluid 


'  ANATOMY  I  11 

in  which  the  hair  cells  are  bathed.     Otoliths  probably  do 
not  exist  in  the  cristse  acusticse. 

In  some  lower  animals,  besides  the  maculae  of  the 
utricle  and  saccule,  there  is  also  a  third  structure  similar 
to  these — the  lagena — which  likewise  contains  otoliths. 
In  certain  fishes  the  otoliths  are  stones  of  1  cm  in  size. 
The  plane  of  the  macula  utriculi  corresponds  roughly  with 
that  of  the  external  semicircular  canal.  In  the  uj)right 
position  it  is  inclined  backward  at  an  angle  of  45°.  Ac- 
cording to  Ketzius  3  the  long  axis  of  the  macula  utriculi 
in  men  is  directed  from  in  front  upward  and  inward  and 
(the  short  axis)  backward,  downward,  and  outward,  the 
general  plane  being  about  horizontal.  The  long  axis  of 
the  saccule  is  almost  vertical,  and  is  directed  from  with- 
out upward  and  inward,  the  short  axis  being  directed 
from  before  backward.  The  macula  is  situated  upon  its 
mesial  surface  (Retzius).  The  plane  of  the  macula 
sacculi  runs  from  above  and  behind  forward  and  down- 
ward in  an  antero-posterior  direction,  at  about  an  angle  of 
45°.  The  lagena  of  lower  animals  permits  vertical  dis- 
placement of  its  otolith,  while  the  maculae  of  the  utricle 
and  saccule  are  roughly  horizontal,  and  at  right  angles  to 
each  other  (Piersol*).  The  hairs  of  the  maculae  of  the 
utricle  and  saccule  are  stiffer  and  shorter  than  those  of 
the  cristae  of  the  ampullae,  and  are  held  together  by  a 
stiffer  mass  of  otoconium,  which,  however,  is  not  gelati- 
nous, but  of  otolithic  composition.  Yerworn  ^  proposed 
the  name  staloliths  for  the  otoliths  of  the  utricle  and 
saccule,  and  called  the  analogous  organs  in  certain  lower 
forms  statocysts,  thus  assuming  that  the  function  of  these 
organs  is  exclusively  static,  as  distinguished  from  the 
dynamic  function  of  the  semicircular  canals.  Clarke,^ 
after  a  comparative  study  of  the  otolithic  and  related 
structures,  concludes  that  whilst  the  otolithic  structures 
are  mainly  statical  in  function,  they  are  not  exclusively 
so,  and  may  function  dynamically  as  well.  With  the 
exception  of  the  maculae  of  the  utricle  and  saccule  no  part 
of  the  vestibular  wall  is  supplied  with  nerve  terminals  of 
the  eighth  nerve, 


CHAPTER  II 

THE   EIGHTH   NERVE 

The  eighth  nerve  consists  of  two  portions — the  coch- 
lear, or  true  nerve  of  hearing,  and  the  vestibular,  which 
is  concerned  with  equilibration.  Traced  from  the  brain 
toward  the  ear,  the  eighth  nerve  arises  at  its  superficial 
origin  by  two  roots :  a  mesial — radix  vestibularis — and  a 
lateral — radix  cochlearis — which  embrace  the  inferior 
cerebellar  peduncle,  the  mesial  root  passing  to  the  inner, 
and  the  lateral  root  to  the  outer  side  of  the  peduncle. 
The  nerve  thus  formed  by  the  union  of  these  two  roots 
leaves  the  surface  of  the  brain-stem  at  the  posterior  bor- 
der of  the  pons,  where  it  is  adherent  to  the  middle  cere- 
bellar peduncle.  To  its  inner  side,  and  closely  associated 
with  it,  are  the  motor  and  sensory  roots  of  the  facial 
nerve,  which  lie  within  a  groove  on  the  mesial  surface  of 
the  eighth,  and  with  it  enter  and  traverse  the  internal 
auditory  canal.  Within  the  latter  the  eighth  nerve  sepa- 
rates into  two  divisions,  of  which  the  superior  and  larger 
is  the  vestibular  nerve  (n.  vestibuli),  and  the  inferior 
and  smaller  the  cochlear  (n.  cochleae).  Although  in  a 
general  way  these  divisions  continue  the  corresponding 
roots,  this  agreement  as  to  the  source  of  their  fibres  is  not 
complete,  since  strands  of  the  vestibular  fibres  are  incor- 
porated with  the  cochlear  nerve.  On  reaching  the  bottom 
of  the  internal  auditory  canal,  the  facial  nerve  enters  the 
facial  canal,  whilst  the  fibres  of  the  eighth  nerve  disap- 
pear through  apertures  in  the  lamina  cribrosa,  to  reach 
the  several  parts  of  the  membranous  labyrinth.  In  the 
internal  auditory  canal  the  vestibular  and  facial  trunks 
are  connected  (fila  anastomica)  by  a  branch,  which  passes 
from  the  pars  intermedia  to  the  vestibular  nerve,  and  by 
one  from  the  latter  to  the  geniculate  ganglion.  These 
apparent  communications  between  the  seventh  and  eighth 

12 


ANATOMY  13 

nerves  are,  in  fact,  only  aberrant  strands  of  facial  fibres 
that  return  to  the  seventh  after  temporary  association 
with  the  eighth. 

The  vestibular  nerve  divides  into  three  terminal 
branches,  which  pass  through  the  apertures  in  the  cribri- 
form plate,  above  the  falciform  crest,  and  supply  the  utri- 
cle and  the  superior  and  external  semicircular  canals. 
Not  all  the  fibres  of  the  vestibular  root,  however,  are  in- 
cluded in  these  branches,  since  of  the  three  branches 
given  off  by  the  vestibular  nerve,  two,  viz.,  those  of  the 
saccule  and  posterior  semicircular  canal,  are  incorporated 
v/ith  the  cochlear  fibres,  and  seemingly  are  derived  from 
the  cochlear  nerve.  The  remaining  branch  of  the  cochlear 
nerve  contains  the  cochlear  fibres  proper,  which  traverse 
the  numerous  foramina  of  the  tractus  spiralis  foraminosus 
and  the  central  canal  of  the  modiolus,  to  supj^ly  the  organ 
of  Corti. 

The  fibres  of  the  eighth  nerve  are  afferent.  Hence 
they  are  processes  (axones)  of  nerve  cells,  situated  some- 
where along  the  course  of  the  nerve.  The  real  origin  of 
the  nerve  fibres,  therefore,  is  to  be  sought  in  the  ganglia, 
occurring  in  the  divisions  of  the  nerve. 

The  true  cochlear  fibres  arise  within  the  cochlea  as 
axones  of  the  cells  of  the  spiral  ganglion,  or  ganglion  of 
Corti  (g.  spirale).  This  structure  consists  of  a  series  of 
bipolar  neurones,  which  occupies  the  spiral  canal  in  the 
base  of  the  lamina  spiralis.  The  dendritic  processes  of 
these  cells  begin  as  fine  fibrils,  which  lie  in  close  relation 
with  the  neuro-epithelial  cells,  comprising  the  inner  and 
outer  hair  cells  of  the  organ  of  Corti.  Leaving  the  hair 
cells  as  non-medullated  fibres,  they  traverse  the  foramina 
nervosa  of  the  labium  tympanicum,  at  which  point  they 
become  medullated  when  they  interlace  to  form  a  flat 
feltworkthat  lies  between  the  layers  of  the  lamina  spiralis, 
and  soon  assemble  to  form  bundles  which  pass  to  the  cells 
of  the  ganglion  spirale,  each  fibre  probably  joining  its 
individual  cell.  Leaving  the  ganglion,  the  axones  of  its 
cells  enter  the  bony  canals  within  the  modiolus,  from 
which  they  emerge  as  the  tractus  spiralis  foraminosus, 
and  are  collected  into  a  single  bundle — the  cochlear  nerve 
proper.  This  latter,  however,  soon  receives  two  acces- 
sions, one  of  which  consists  of  fibres  from  the  saccule,  the 


14  SEMICIRCULAR   CANALS 

other  from  the  posterior  semicircular  canal.  These 
accessions  are  in  reality  parts  of  the  vestibular  nerve 
and,  beyond  their  temporary  companionship  have  nothing 
to  do  with  the  cochlear  root. 

On  reaching  the  medulla  the  cochlear  fibres  come  into 
relation  with  their  nucleus  of  reception,  which  includes 
two  superficial  aggi-egations  of  nerve  cells  that  collectively 
constitute  the  acoustic  nucleus.  The  latter  consists  of 
two  parts,  of  which  one — the  ventral  cochlear  nucleus, 
also  called  the  accessory  acoustic  nucleus — lies  ventral  to 
the  inferior  cerebellar  peduncle ;  and  the  other — the  lateral 
cochlear  nucleus,  or  tuberculum  acusticum,  rests  upon  the 
dorso-lateral  surface  of  the  peduncle,  and  occupies  the 
extreme  outer  part  of  the  triangular  acoustic  area,  seen  in 
the  lateral  angle  of  the  floor  of  the  fourth  ventricle.  The 
greater  number  of  cochlear  fibres  end  in  arborizations 
around  the  stellate  cells  of  the  ventral  ganglion,  whilst 
others  terminate  in  relation  with  the  more  elongated 
fusiform  cells  of  the  lateral  nucleus.  From  the  neurones 
of  these  subdivisions  of  the  reception  nucleus,  the  audi- 
tory pathway  is  continued  as  two  chief  tracts — the  axones 
of  the  cells  of  the  ventral  nucleus  passing  for  the  most 
part  ventral  to  the  restiform  body  and  the  special  root  of 
the  trigeminus  to  form  the  corpus  trapezoides,  whilst  those 
from  the  lateral  nucleus  sweep  around  the  outer  surface 
of  the  restiform  body,  and  then  medially  beneath  the 
ependyma  of  the  floor  of  the  fourth  ventricle,  where  they 
show  with  varying  degrees  of  distinctness  as  the  striae 
acusticse.  The  corpus  trapezoides — the  conspicuous  trans- 
verse tract  that  separates  the  tegmental  from  the  ventral 
region  of  the  pons  in  its  superior  part — is  formed  chiefly 
by  the  axones  of  the  cells  within  tlie  central  cochlear 
nucleus,  supplemented  by  a  limited  number  of  fibres  that 
spring  from  the  lateral  nucleus.  In  addition  it  contains 
axones  from  the  large  cells  found  within  the  trapezoid 
body  on  each  side  of  the  middle  line  that  constitute  the 
nucleus  trapezoideus.  In  close  relation  with  the  dorsal 
surface  of  the  corpus  trapezoides,  within  the  superior 
olive  and  on  either  side  of  the  median  raphe,  lies  the 
superior  olivary  nucleus  (nuc.  olivarius  superior) ,  a  col- 
lection of  nerve  cells  around  which  many  of  the  cochlear 
fibres,  chiefly  from  the  opposite  but  also  from  the  same 


ANATOMY  15 

side,  end  and  from  which  the  tract  of  the  lateral  fillet 
principally  takes  origin.  Not  all  the  fibres  arising  from 
the  superior  olivary  nucleus,  however,  enter  the  lateral 
fillet.  A  considerable  number  leave  the  dorsal  surface  of 
the  nucleus,  and  as  its  peduncle  pass  to  the  abducent 
nucleus  (v.  Bechterew  considers  these  fibres  as  cerebello- 
fugal  paths  to  the  abducens  nucleus) ,  and  by  way  of 
the  posterior  longitudinal  fasciculus  to  the  nuclei  of  the 
other  ocular  nerves.  In  this  manner  it  is  asserted  the 
reflex  paths  are  established,  by  which  the  motor  nerves, 
including  probably  the  facial,  are  brought  under  the 
influence  of  auditory  impulses. 

There  are  reasons,  however,  for  rejecting  this  simple, 
almost  direct  relation  between  the  eighth  nerve  and  the 
nuclei  of  the  eye  muscles.  Movements  of  the  eyes  in 
response  to  a  loud  sound  are  not  simple  reflex  movements, 
but  complex,  coordinated  movements,  associated  usually 
with  other  movements,  e.g.,  turning  of  the  head  and  eyes 
to  the  source  of  the  sound,  accompanied  by  a  general 
movement  of  withdrawal  of  the  head  and  upper  part  of 
the  body.  Such  complex  purposive  movements  could 
hardly  take  j)lace  through  direct  paths  from  the  auditory 
to  the  ocular  and  other  nuclei  without  the  intervention  of 
some  higher  harmonising  mechanism.  Moreover,  in 
Ferrier's^  experiments,  stimulation  of  the  auditory  area 
in  the  temporal  lobe  caused  the  animal  to  turn  the  head 
and  eyes  in  the  direction  of  the  ear  of  the  opposite  side. 
This  interesting  experiment  shov»"s  that  the  main  relation 
between  the  auditory  nerve  proper  and  the  cerebral  cortex 
is  a  crossed  one.  It  also  shows  that  reflex,  coordinated 
turning  of  the  head  and  eyes  in  response  to  auditory 
stimuli  may  take  place  along  other  ]3aths  than  the  direct 
one  mentioned;  that  is,  in  a  downward  course,  possibly 
through  the  medium  of  the  cerebellum. 

Within  the  tract  of  the  fillet,  a  short  distance  beyond 
the  superior  olive,  is  encountered  a  group  of  nerve  cells, 
the  nucleus  of  the  lateral  fillet  (nucleus  lemnisci  lateralis) . 
Whilst  numerous  additions  to  the  fillet  are  received  from 
these  cells,  their  relation  to  the  cochlear  fibres  is  uncer- 
tain. The  lateral  fillet  will  be  more  fully  described  later 
on.  It  is  sufficient  to  note  here  that  in  so  far  as  the 
auditory  (cochlear)  fibres  are  concerned,  the  tract  termi- 


16  SEMICIRCULAR   CANALS 

nates  chiefly  in  the  inferior  collicuhis  of  the  quadrigemina 
and  in  the  median  geniculate  body.  In  addition  to  its 
constituents  through  the  corpus  trapezoides  the  lateral 
fillet  receives  considerable  accessions  of  cochlear  fibres  by 
way  of  the  striae  acusticse.  These  strands  consist,  for  the 
most  part,  of  the  axones  of  the  cells  lying  within  the 
tuberculum  acusticum ;  but  to  a  limited  extent  also  of  the 
axones  of  the  ventral  cochlear  nucleus,  which  wind  over 
the  latero-dorsal  surface  of  the  inferior  cerebellar  peduncle, 
pass  medially  beneath  the  ependyma  of  the  floor  of  the 
fourth  ventricle,  as  far  as  the  median  groove;  and,  cross- 
ing to  the  opposite  side,  sweep  ventrally  through  the 
dorsal  region  of  the  medulla  or  pons,  to  join  the  tract  of 
the  lateral  fillet,  and  so  proceed  in  company  with  the 
other  cochlear  fibres  to  the  higher  levels.  Not  all  the 
component  fibres  of  the  acoustic  strise  follow  the  lateral 
fillet;  some  of  them,  after  decussation,  turn  brainward, 
possibly  joining  the  mesial  fillet,  whilst  others  may 
enter  the  posterior  longitudinal  fasciculus  to  assist  in 
establishing  the  reflex  paths,  influencing  the  motor 
nerves.  The  auditory  paths,  by  which  impulses  from  the 
organ  of  Corti,  travelling  along  the  cochlear  fibres  reach 
the  cerebral  cortex,  are  as  follows : 

1.  Peripheral  neurones  of  the  ganglion  spirale  whose 
axones — the  cochlear  fibres — pass  to  the  reception  nu- 
cleus, composed  of  the  ventral  and  lateral  cochlear 
nuclei. 

2.  The  neurones  of  the  cochlear  nuclei  send  their 
axones — (a)  By  way  of  the  corpus  trapezoides  to  the 
superior  olivary  nucleus,  chiefly  of  the  opposite  side  or 
to  the  lateral  fillet,  or  its  nucleus  without  interruption  in 
the  olive,  (b)  By  way  of  the  stria3  acusticse  through  the 
tegmentum,  to  join  the  trapezoidal  fibres. 

3.  The  neurones  of  the  superior  olivary  nucleus,  or  of 
the  fillet  nucleus,  whose  axones  pass  by  way  of  the  lateral 
fillet,  (a)  To  the  cells  within  the  inferior  colliculus,  or 
(b)  without  interruption  through  the  inferior  brachium 
to  the  cells  within  the  median  geniculate  body. 

4.  The  neurones  of  the  inferior  colliculus  and  of  the 
median  geniculate  body  whose  axones  pass  as  the  audi- 
tory  radiation  to  tlie  auditory  cortical  area  within  the 
temponil  loho  of  the  cerebrum.     The  exact  limitations  of 


ANATOMY  17 

tne  auditory  area  are  still  uncertain,  but  the  most  im- 
portant part  of  it  includes  the  superior  temporal  and  the 
subjacent  part  of  the  middle  temporal  convolution. 

The  cochlear  fibres  that  do  not  undergo  decussation 
ascend  through  the  lateral  fillet  of  the  same  side,  and 
eventually  establish  cortical  relations  with  the  corre- 
sponding cerebral  hemisphere.  From  the  foregoing  it  is 
manifest  that  the  auditory  area  is  chiefly  connected  with 
the  cochlea  of  the  opposite  side.  This  crossed  relation  is 
emphasized,  for  there  are  sufficient  reasons  for  asserting 
positively  the  existence  of  a  similar  crossed  relation  be- 
tween the  cerebellum  and  the  semicircular  canals  and 
vestibule,  as  will  appear  later. 

The  fibres  of  the  vestibular  portion  of  the  eighth  nerve 
are  the  axones  of  the  bipolar  nerve  cells  situated  within 
the  small  vestibular  (g.  vestibulare)  or  Scarpa's  ganglion, 
which  lies  at  the  bottom  of  the  internal  auditory  canal. 
The  dendrites  of  these  cells  constitute  the  five  branches  of 
distribution  of  the  vestibular  nerve,  and  pass  through  the 
various  openings  in  the  inner  wall  of  the  bony  labyrinth, 
as  above  described,  to  reach  the  maculae  acusticse  within 
the  saccule  and  utricle  and  the  cristse  acusticse  of  the 
ampullae  of  the  semicircular  canals,  where  the  nerve  fila- 
ments are  in  intimate  relation  with  the  neuro-epithelium. 
The  centrally  directed  axones  of  the  neurones  supplying 
the  utricle  and  the  superior  and  external  semicircular 
canals  become  consolidated  to  form  the  vestibular  nerve 
of  descriptive  anatomy.  Those  from  the  saccule  and  pos- 
terior semicircular  canal  join  the  cochlear  fibres,  and  with 
these  course  within  the  cochlear  nerve  until  the  latter 
unites  with  the  vestibular  to  form  the  common  auditory 
or  eighth  nerve  trunk.  Where  the  common  trunk  sepa- 
rates into  its  two  roots  the  vestibular  fibres  leave  the 
cochlear,  and  permanently  assume  their  natural  com- 
panionship with  the  remaining  fibres  of  the  vestibular 
root. 

The  vestibular  fibres  enter  the  brain  stem  at  a  slightly 
higher  level  than  those  of  the  cochlear  root  lying  mesial 
to  the  latter  and  the  ventral  cochlear  nucleus,  and  pass 
dorsally  within  the  pons,  between  the  inferior  cerebellar 
peduncle  and  the  spinal  trigeminal  root.  On  reaching  a 
level  dorsal  to  the  latter,  the  vestibular  fibres  divide  into 


18  SEMICIRCULAR   CANALS 

short  upward  and  longer  downward  coursing  branches 
which,  after  condensing  into  an  ascending  and  descend- 
ing root  respectively,  end  in  arborizations  around  the 
cells  of  the  vestibular  nucleus  of  reception.  The  exact 
extent  a.nd  constitution  of  this  nucleus  which  underlies 
the  area  acustica  in  the  floor  of  the  fourth  ventricle  are 
uncertain,  since  the  neurones  directly  related  to  the  ves- 
tibular fibres  contribute  only  a  part  of  those  contained 
within  a  large  diffuse  complex  of  cells  and  fibres,  many 
of  whose  constituents  probably  have  only  an  indirect  con- 
nection with  the  vestibular  nerve.  Sabin^  successfully 
reconstructed  this  complex,  which  comprises  two  general 
parts: 

1.  An  extended,  irregularly  triangular  mass  of  cells 
lying  for  the  most  part  mesial  to  the  tract  formed  by  the 
ascending  and  descending  branches  of  the  vestibular  fibres 
and, 

2.  A  smaller  mass  of  cells  which  lies  above  the  larger 
one,  and  partly  to  the  outer  side  of  the  tract  of  the 
vestibular  fibres.  The  apex  of  the  large  triangular  mass 
approaches  the  middle  line,  and  its  superior  and  inferior 
basal  angles  are  prolonged  upward  and  downward  along 
the  vestibular  tract. 

Examined  microscopically  the  large  mass  is  found  to 
include  three  subdivisions : 

(a)  A  tapering,  caudally  directed  nucleus,  which  con- 
tinues the  inferior  angle  along  the  descending  vestibular 
root. 

(b)  An  extended  triangular  nucleus  that  includes  the 
greater  part  of  the  large  triangular  mass. 

(c)  An  irregular  pyramidal  nucleus  that  prolongs  up- 
ward the  superior  angle.  The  first  of  these  subdivisions 
(a)  is  known  as  the  spinal  vestibular  nucleus  (nuc. 
spinalis  n.  vestibularis) ;  the  second  (b)  as  the  median 
vestibular  nucleus  (nuc.  medialis  n.  vestibularis) ,  also  as 
the  chief  nucleus  or  the  triangular  nucleus;  and  the  third 
(c)  as  the  superior  vestibular  nucleus,  or  the  nucleus  of 
V.  Bechterew.  The  small  mass  (2)  corresponds  with  the 
lateral  vestibular  nucleus  (nuc.  lateralis  n.  vestibularis), 
or  the  nucleus  of  Deiters. 

The  fibres  of  the  descending  root  end  around  the 
neurones  within  the  spinal  nucleus  in  a  manner  similar 


AMATOMY  19 

to  that  in  which-the  constituents  of  the  spinal  root  of  the 
trigeminus  terminate  in  relation  with  the  neurones  within 
the  substantia  gelatinosa,  whilst  those  of  the  ascending 
vestibular  root  end  around  the  cells  within  the  remaining 
vestibular  nuclei.  Ferrier  and  Turner,  however,  observed 
that  after  section  of  the  eighth  nerve  the  descending  ves- 
tibular root  did  not  degenerate,  whilst  Bruce  traced  the 
fibres  to  the  cuneate  nucleus.  (See  Vestibular  connec- 
tions.) 

Although  much  uncertainty  and  conflict  of  opinion 
exist  as  to  the  details  of  the  secondary  paths  by  which 
the  impulses  carried  by  the  vestibular  fil^res  are  dis- 
tributed, it  may  be  accepted  that  fibres  pass  from  the 
nuclei  of  reception: 

(a)  To  the  cerebellum,  chiefly  to  the  roof  nucleus  of 
the  o]3posite  side,  and  possibly  to  the  nucleus  globosus 
and  emboUiformis  as  constituents  of  the  nucleo-cerebellar 
tract,  by  which  impulses  of  equilibration  are  carried  to 
the  great  coordinating  centres.  (See  note  to  Vestibular 
connections.) 

(b)  As  arcuate  fibres  ventro-medially  into  the  tegmen- 
tum of  the  pons  across  the  middle  line,  bending  upward 
or  downward  to  reach  other  levels,  some  fibres,  however, 
remaining  on  the  same  side.  From  the  character  of  the 
impulses  it  is  probable  that  only  relatively  few  vestibular 
fibres  join  the  median  fillet  to  ascend  to  the  optic  thala- 
mus.    Other  connections  of  the  nuclei  include: 

(c)  Commissural  fibres  between  V.  Bechterew's  nucleus 
of  either  side. 

(d)  Fibres  to  the  abducent  nucleus.  (But  see  sum- 
mary of  Vestibular  connections.) 

(e)  Crossed  and  uncrossed  fibres  fromDeiters'  nucleus 
to  the  posterior  longitudinal  fasciculus ;  and 

(f)  Fibres  from  the  same  nucleus  to  the  spinal  cord. 
Not  all  the  neurones  of  Deiters'  nucleus  are  concerned 

in  transmitting  afferent  impulses  to  the  cerebellum,  for 
many  are  links  in  the  path  by  which  cerebellar  cells  exer- 
cise coordinating  influence  over  the  root  cells  of  the  spinal 
nerves.  Starting  in  the  cerebellum  such  efferent  impulses 
are  carried  by  fibres  that  descend  through  the  median  part 
of  the  inferior  cerebellar  peduncle,  and  probably  end 
around   certain    of   the   cells    within   Deiters'    nucleus. 


20  SEMICIRCULAR   CANALS 

Fr.om  these  cells  in  turn  originate  the  fibres  of  the  vesti- 
biilo-spinal  tract  which,  after  traversing  the  medulla,  enter 
the  antero-lateral  column  of  the  cord,  and  end  in  relation 
with  the  motor  root  cells.  A  shorter  and  more  direct 
path  for  vestibular  reflexes  may  probably  be  formed  by 
the  collaterals  of  the  vestibular  fibres  that  end  around  the 
spinal  neurones  of  Deiters'  nucleus;  but  the  objection 
already  put  forward  against  the  simple  direct  connection 
between  afferent  cochlear  fibres  and  the  oculo-motor  centres 
holds  as  well  here  as  in  the  case  of  vestibular  fibres.  Such 
connections  cannot  account  for  the  more  complex  coordi- 
nated movements  of  equilibration  which  postulate  a  higher 
coordinating  mechanism.  The  vestibular  and  cochlear 
nuclei  are  nutrient  relay  centres — coordinating  centres  of 
a  lower  order  perhaps  but  related  to,  and  acting  in  accord 
with,  higher  coordinating  centres  that  regulate  and  con- 
trol the  more  complicated  movements  consequent  on  coch- 
lear or  vestibular  irritation.  In  those  cases  where  there 
seems  to  be  a  direct  connection  between  the  vestibular 
fibres  and  the  motor  centres,  e.g.,  those  fibres  mentioned 
as  going  to  the  abducent  nucleus,  it  is  probable  that  such 
fibres  are  mainly  efferent  and  carry  impulses  from  the 
cerebellum  or  other  higher  centres,  which  coordinate  the 
movements  of  the  eyes  with  the  movements  executed  by 
other  muscles  in  response  to  labyrinthine  stimulation. 
The  same  has  to  be  said  of  many  fibres  in  the  posterior 
longitudinal  fasciculus,  which,  undoubtedly,  convey  co- 
ordinating impulses  that  harmonise  the  actions  of  motor 
nerve  centres  situated  at  some  distance  from  each  other, 
a  notable  instance  being  that  of  the  abducens  centre, 
which  works  in  harmony  with  the  centre  for  the  internal 
rectus  muscle  of  the  opposite  side.  In  the  nystagmic 
movements  observed  in  irrigations  of  the  external  audi- 
tory canal,  undoubtedly  the  fibres  from  Deiters'  nucleus 
to  the  posterior  longitudinal  fasciculus  play  an  important 
role;  but,  as  before  stated,  these  fibres  probably  do  not 
represent  a  direct  immediate  connection  between  the  ves- 
tibular fibres  and  the  posterior  longitudinal  fasciculus, 
but  are  to  be  considered  in  part  at  least  as  efferent  fibres 
from  the  cerebellum  or  other  coordinating  centre. 

In  fishes  the  vestibular  nerve  is  in  close  functional 
relation  with  the  mesencephalic  centres  of  the  opposite 


ANATOMY  21 

side  (Loeb  ^^) ,  whilst  almost  all  the  optic  fibres  pass  to 
the  same  centres  (Parsons  *^) .  In  fishes,  therefore,  and  in 
the  lower  forms  of  animals  generally  it  is  reasonable  to 
assign  important  functions  in  the  maintenance  of  equili- 
brium to  the  mesencephalic  centres. 


CHAPTER  III 

THE   REMAINING   CRANIAL   NERVES 

Of  the  remaining  cranial  nerves  the  first  or  olfactory- 
is  the  only  sensory  nerve  in  man  in  which  the  neurones 
(cell  bodies)  of  the  first  order  are  situated  on  the  surface, 
like  tlie  sensory  cells  of  some  of  the  invertebrates.  These 
latter  cells  represent  the  cell  bodies  of  the  posterior  spinal 
ganglia,  which  have  wandered  to  the  surface  epithelium 
(Retzius*^).  For  the  central  relations  of  the  olfactory 
nerve  see  "the  rhinencephalon"  in  the  synopsis  of  ana- 
tomical connections. 

The  second  or  optic  nerve  is  not  a  true  nerve,  but  a 
part  of  the  brain  substance.  The  true  optic  nerve  com- 
ponents are  the  sensory  neurones  of  the  first  order  lying 
within  the  retina  itself.  As  the  dorsal-spinal-ganglion 
cells  emigrate  from  the  neural  crest  at  an  early  age  to 
form  the  neurones  of  the  first  order  of  the  sensory  spinal 
nerves,  and  lose  their  connection  with  the  cord  to  regain 
it  later  on,  it  is  manifest  that  the  analogy  between  the 
optic  and  the  sensory  spinal  elements  is  incomplete,  since 
the  retina  develops  entirely  from  the  invaginated  optic 
vesicle.  For  the  central  connections  of  the  optic  nerve 
see  "Anatomical  Synopsis." 

The  third,  fourth,  and  sixth  nerves  are  purely  motor, 
and  arise  from  their  respective  nuclei.  As  neuro-tendi- 
nous  organs,  similar  to  the  Golgi-Mazzini  corpuscles,  have 
been  demonstrated  in  the  tendons  of  the  external  ocular 
muscles,  and  as  the  degree  of  convergence  of  the  eyeballs 
has  much  to  do  with  accommodation  reflexes,  it  is  prob- 
able that  the  third  nerve  has  afferent  paths  for  accommo- 
dation reflexes  and  for  purposes  of  reciprocal  innervation. 

The  nucleus  of  tlie  third  nerve  is  medially  situated 
deep  within  the  gnjy  matter  of  the  aqueduct  of  Sylvius, 
near  the  dorsal  surface  of  the  posterior  longitudinal  fasci- 

22 


ANATOMY  23 

cuius.  The  nucleus  is  6-8  mm  long,  and  extends  from 
the  level  of  the  caudal  pole  of  the  superior  colliculi  (from 
underneath  superior  colliculi  and  part  of  third  ventricle, 
according  to  Quain^^)  almost  to  the  level  of  the  fourth 
nucleus,  from  which  it  is  separated  by  a  narrow  interv^al. 
The  grouping  of  the  nerve  cells  of  the  third  nucleus  is  as 
follows : 

1.  A  paired  group,  consisting  of  long  columns  of  cells 
— the  chief  nuclei — extending  along  the  dorsal  surface  of 
the  posterior  longitudinal  fasciculi.  These  chief  nuclei 
are  subdivided  into  (a)  dorsal  (lateral)  and  (b)  ventral 
(mesial)  cell  groups.  Dislocated  groups  of  cells  of  the 
chief  nucleus  lie  scattered  among  and  beneath  the  fibres 
of  the  posterior  longitudinal  fasciculus. 

2.  Dorsal  to  the  chief  nucleus  and  overlying  the  pos- 
terior-median surface  is  the  tapering  column  of  small 
nerve  cells — the  Edinger-Westphal  nucleus.  The  mass  of 
this  nucleus  is  thicker  above  than  below  (caudad) ,  and  is 
divided  into  dorso-lateral  and  ventro-median  portions  at 
the  caudal  pole,  though  fused  at  the  cephalic  extremity. 
There  is  question  as  to  whether  the  Edinger-Westphal 
nucleus  is  related  to  the  third  nerve.  In  the  dorsal 
(inferior)  group  of  cells  maybe  distinguished  six  second- 
ary groups.  Two  of.  these  lie  lateral  to  the  others,  and 
somewhat  dorsally.  The  remaining  four  are  placed  more 
mesially  and  one,  which  is  in  the  middle  line — the 
nucleus  medialis — is  common  to  the  oculo-motor  nerve  of 
each  side.  Experiments  on  animals  and  pathological 
observations  in  man  seem  to  show,  that  the  oculo-motor 
centres  are  grouped  as  above;  that  is,  that  they  are 
divided  into  a  superior  and  an  inferior  or  dorsal  group, 
and  again  into  a  mesial  and  a  lateral  group.  The  ante- 
rior (superior)  part  of  the  oculo-motor  nucleus  has  smaller 
cells  than  the  rest  of  the  nucleus,  and  extends  forward 
into  the  wall  of  the  third  ventricle.  Hensen  and  Volck- 
ers  ^^  have  shown  by  direct  application  of  the  electrodes  in 
the  dog  that  most  anteriorily  in  the  wall  of  the  third  ven- 
tricle is  the  centre  for  accommodation.  Behind  this,  and 
more  laterally  situated  than  the  former,  is  the  centre  for 
constriction  of  the  iris.  At  the  junction  of  the  third 
ventricle  with  the  aqueduct  of  Sylvius  is  the  centre  for  the 
rectus  internus,  behind  which,  in  order  backward,  are  the 


24  SEMICIRCULAR   CANALS 

centres  for  the  rectus  superior,  levator  palpebrse  superioris, 
rectus  inferior,  and  lastly  that  of  the  obliquus  superior. 
The  clinical  observations  of  Kahler  and  Pick,  and  those 
of  Starr,  indicate  that  the  levator  palpebrae,  rectus  supe- 
rior, and  obliquus  inferior  are  innervated  from  the  dorsal 
(dorso-lateral)  group,  and  the  rectus  internus  and  rectus 
inferior  from  the  ventro-mesial  group  in  order  from  above 
downward  (caudad). 

v.  Bechterew  ^'  from  his  observations  following  irrita- 
tion of  the  posterior  wall  of  the  third  ventricle  and  of  the 
floor  of  the  aqueduct  of  Sylvius  concluded  that  the  third 
nucleus  consists  of  two  larger  groups — one  paired  and 
one  unpaired — and  of  two  smaller  paired  accessory  groups. 
The  former — larger  groups — contain  the  main  nucleus, 
and  are  laterally  and  ventrally  in  relation  with  the  pos- 
terior longitudinal  fasciculus.  About  the  level  of  the 
junction  of  the  middle  with  the  anterior  third  of  the 
nucleus  is  the  median  unpaired  group  and  the  dorso- 
lateral paired  groups.  The  anterior  (superior)  groups 
are  related  to  accommodation  and  pupillary  constriction. 
The  posterior  group  is  subdivided  into  a  lateral  group  for 
the  levator  palpebrse,  superior  rectus,  and  inferior  ob- 
lique, and  a  median  group  for  the  internal  and  inferior 
rectus. 

From  the  uniformity  of  the  findings  given  above  the 
grouping  of  the  centres  in  the  third  nucleus  may  be 
accepted  as  proven.  Tsuchida,^'*  who  recently  (1906) 
investigated  the  whole  subject,  denies  the  constant  exist- 
ence of  a  well-marked,  unpaired,  median  group,  as 
described  by  Perlia  and  others,  but  admits  the  existence 
of  broken  groups  of  medially  placed  cells,  especially  in 
the  upper  and  lower  thirds  of  the  nucleus.  The  oculo- 
motor fibres,  according  to  Tsuchida,  originate  from  vari- 
ous portions  of  the  third  nucleus  without  limited  relations 
to  distinct  groups. 

The  nucleus  of  Darkschweitsch,  which  is  a  laterally 
situated  group  of  cells  beginning  in  the  floor  of  the  third 
ventricle  and  extending  caudallyas  far  as  the  upper  third 
of  the  chief  nucleus,  is  no  longer  regarded  as  having 
direct  relations  with  the  third  nerve.  It  is  in  intimate 
relation  with  the  posterior  longitudinal  fasciculus, 
amongst  the  fibres  of  which  its  cells  to  a  great  extent  lie. 


ANATOMY  25 

Hence  it  is  often  called  the  nucleus  of  the  posterior  longi- 
tudinal fasciculus. 

It  is  stated  as  probable  that  the  oculo-motor  fibres 
decussate  in  the  caudal  portion  of  the  chief  nucleus. 
Tsuchida^*  and  others  maintain  that  some  decussation 
takes  place  throughout  the  greater  part  of  the  nucleus. 

The  connections  of  the  third  nucleus  are  as  follows: 

1.  With  the  cerebral  cortex :  (a)  With  the  posterior  por- 
tion of  the  second  and  third  frontal  convolutions,  chiefly 
of  the  opposite  side.  This  connection  is  direct  via  the 
corona  radiata,  internal  capsule,  and  cerebral  peduncle, 
and  was  first  demonstrated  by  Ferrier,^and  independently 
byMunk.  (b)  With  the  occipital  cortex  about  the  visual 
area.  This  connection  is  also  mainly  crossed,  and  repre- 
sents a  motor  ocular  path,  as  demonstrated  by  Schafer 
and  Brown. ^^  The  path  is  indirect  via  the  optic  radia- 
tion, superior  brachium,  and  su^^erior  colliculi.  Ferrier 
also  got  ocular  movements  from  this  area,  but  considered 
them  as  associated  movements  (synkineses) . 

2.  With  the  primary  visual  centres  via  the  superior 
colliculi. 

8.  With  the  nuclei  of  the  fourth  and  sixth  cranial 
nerves  and  with  Deiters'  nucleus.  These  connections 
are  supposed  to  be  by  way  of  the  posterior  longitudinal 
fasciculus. 

4.  With  the  nucleus  of  the  facial  nerve  via  the  pos- 
terior longitudinal  fasciculus.  This  connection  is  assumed 
to  explain  the  associated  action  of  the  third  and  seventh 
nerves  in  contractions  of  the  orbicularis  palpebrarum  and 
corrugator  supercilii  muscles. 

As  previously  stated,  the  simple  direct  communication 
between  the  ocular  nuclei  and  Deiters'  nucleus  cannot  be 
accepted  as  fully  explaining  the  coordinated  actions  of 
the  various  functionally  related  structures.  Thus  Duval 
and  Laborde  ^^  showed  that  irritation  of  the  sixth  nucleus 
caused  lateral  conjugate  movements  of  the  eyeballs,  and 
explained  the  results  by  asserting  that  the  sixth  nucleus 
sends  fibres  through  the  posterior  longitudinal  fasciculus 
to  the  centre  for  the  opposite  internal  rectus  in  the  third 
nucleus.  But  Schafer  ^^  whilst  admitting  that  fibres  from 
the  posterior  longitudinal  fasciculus  enter  the  sixth  and 
third  nuclei,  insists  that  such  fibres  end  in  these  nuclei, 


26  SEMICIRCULAR   CANALS 

and  that  no  fibres  from  the  sixth  or  third  nucleus  enter 
the  posterior  longitudinal  fasciculus.  The  fibres  of  the 
posterior  longitudinal  fasciculus  to  the  sixth  nucleus 
more  probably  represent  efferent  cerebellar  or  other  paths 
which,  with  similar  fibres  or  collaterals  passing  from  the 
cerebellimi  or  other  centre  to  the  third  and  fourth  nucleus, 
afford  a  more  rational  explanation  of  the  coordinated 
action  of  these  nuclei.  Moreover,  v.  Bechterew^^  con- 
siders the  cerebellar  superior  olivary  tract  which,  through 
the  superior  olives,  makes  connection  with  the  sixth 
nucleus  as  an  efferent  cerebellar  jy-cith  for  ocular  move- 
ments. 

In  a  similar  way,  perhaps,  may  be  explained  the 
coordinated  relation  of  the  seventh  and  third,  as  well  as 
of  the  other  cranial  nerve  nuclei. 

5.  With  the  cerebellum.  These  paths  have  not  been 
satisfactorily  demonstrated,  v.  Bechterew  states  that  a 
continuous  connection  exists  between  the  third  nucleus 
and  the  cerebellum,  by  which  the  latter  becomes  in- 
structed as  to  the  position  of  the  eyeballs  and  the  condi- 
tion of  the  pupil.  These  pathways  lie  in  the  superior 
peduncle  of  the  opposite  side.  The  relation,  therefore, 
between  the  oculo-motor  nucleus  and  the  cerebellum  is  a 
crossed  one. 

V.  Bechterew,  ^^  however,  in  discussing  the  centrifugal 
function  of  the  spinal  bundle  of  the  middle  peduncle  and 
of  the  cerebellar  superior  olivary  tract,  states  that  the 
fibres  passing  in  the  superior  peduncle  to  the  oculo-motor 
nucleus  of  the  opposite  side  are  also  cerebello-efferent  for 
the  control  of  reflex  ocular  movements.  The  relations  of 
the  third  nucleus  to  the  seventh  and  to  the  other  cranial 
nerve  nuclei  are  probably  mainly  through  the  cerebellum 
via  the  superior  peduncle,  and  thence  through  efferent 
cerebellar  paths,  including  those  in  the  posterior  longi- 
tudinal fasciculus. 

The  fourth  nucleus  lies  near  the  middle  line,  just 
caudad  to  the  third  nucleus,  from  which  it  is  separated 
by  a  small  intfjrval.  It  seems  to  lie  in  a  distinct  depres- 
sion on  the  posterior  longitudinal  fasciculus.  It  is  2  mm 
long,  and  ext(m(ls  from  a  point  oy)posite  the  superior 
fxjrder  of  the  inferior  colliculus.  to  the  lower  ])ole  of  the 
colliculus.     It  is  in  relation  with  the  cortex  of  thf?  inferior 


ANATOMY  27 

frontal  convolution  of  the  opposite  side  through  fibres 
that  pass  by  way  of  the  corona  radiata,  internal  capsule, 
and  cerebral  peduncle.  It  is  stated  that  this  nucleus  is 
in  relation  with  the  third  and  sixth  nuclei  through  the 
posterior  longitudinal  fasciculus.  For  reasons  already 
stated,  it  is  preferable  to  consider  these  relations  as  made 
mainly  through  the  cerebellum  or  other  coordinating  cen- 
tre, and  not  directly  by  fibres  passing  between  the  nuclei. 
The  fibres  arising  in  the  nucleus  pass  laterally  and  ven- 
trally  in  the  tegmentum  for  a  short  distance,  and  then 
course  in  a  median  direction  and  dorsalward.  They 
totally,  or  almost  totally,  decussate  in  passing  through  the 
anterior  end  of  the  superior  medullary  velum,  and  emerge 
from  the  surface  of  the  latter  at  the  side  of  the  frenulum 
veli  in  two  small  bundles,  which  pierce  the  pia  and  unite 
to  form  the  trunk  of  the  nerve.  The  fourth  nucleus  does 
not  seem  to  bear  any  close  functional  or  anatomical  rela- 
tion to  that  of  the  seventh. 

The  sixth  nucleus  consists  of  multipolar  cells  lying  in 
the  dorsal  part  of  the  tegmentum  of  the  pons,  and  under- 
neath the  floor  of  the  fourth  ventricle.  It  is  situated 
anterior  to  the  striae  acusticse,  beneath  the  eminentia 
teres,  and  ventral  to  and  within  the  loop  formed  by  the 
fibres  on  their  way  to  form  the  seventh  nerve.  The  sixth, 
like  the  third  and  fourth  nuclei,  is  related  to  the  frontal 
oculo-motor  area  of  the  cerebral  cortex  of  the  opposite 
side.  The  decussation  of  the  cortical  paths  takes  place  at 
the  level  of  the  nucleus,  and,  according  to  some  observers, 
through  the  nucleus.  The  nucleus,  it  is  stated,  is  in  rela- 
tion with  the  third  nucleus  of  the  opposite  side,  and  with 
the  superior  olive,  and  the  cochlear  and  vestibular  nuclei 
through  the  posterior  longitudinal  fasciculus.  For  rea- 
sons already  stated,  these  connections  probably  represent 
in  the  main,  efferent  cerebellar  paths,  i.e.,  part  of  the 
common  paths  originating  in  the  cerebellum,  and  sending 
fibres  or  collaterals  to  each  of  the  associated  nuclei.  The 
sixth  nerve  makes  its  exit  through  the  posterior  part  of 
the  pons,  between  the  latter  and  the  medulla  oblongata. 
In  the  cavernous  sinus  it  is  situated  first  above  and  then 
to  the  outer  side  of  the  carotid  artery,  and  passes  through 
the  superior  orbital  fissure,  to  join  the  external  rectus 
muscle.     The  sixth  is  the  longest  of  the  cranial  nerves. 


28  SEMICIRCULAR   CANALS 

Owing  to  its  length  and  the  course  it  takes  it  is,  of  all  the 
cranial  nerves,  the  most  liable  to  pressure  from  exuda- 
tions, syphilitic  or  other,  occurring  at  the  base  of  the 
brain. 

The  fifth  is  a  mixed  nerve.  It  has  two  nuclei.  The 
sensory  nucleus  is  a  columnar  mass  of  grey  matter  within 
the  lateral  part  of  the  tegmentum,  extending  from  the 
middle  of  the  pons  through  the  entire  length  of  the  me- 
dulla, and  into  the  spinal  cord,  as  low  as  the  second  cer- 
vical segment,  where  it  becomes  continuous  with  the  sub- 
stantia gelatinosa.  Though  the  rounded  upper  part  of 
this  tapering  column  is  called  the  sensory  nucleus  of  the 
fifth  nerve,  the  whole  mass  receives  fibres.  The  fibres  of 
the  fifth  nerve  as  they  approach  this  nucleus  divide  into 
ascending  and  descending  bundles.  The  latter  are  coarser 
than  the  former,  and  form  the  descending  or  spinal  root. 
The  Gasserian  ganglion  contains  the  cell  bodies  of  the 
primary  neurones  of  the  sensory  part  of  the  fifth  nerve, 
this  ganglion  being  the  analogue  of  the  dorsospinal-root 
ganglia  of  the  spinal  nerves. 

The  connections  of  the  sensory  part  of  the  fifth  nerve 
are: 

1.  By  axones  which  cross  the  raphe  from  the  nucleus 
to  the  opposite  mesial  fillet,  ascend  to  the  thalamus  and, 
after  interruption,  proceed  to  the  cortex  cerebri.  It  is 
probable  that  some  fibres  pass  to  the  fillet  of  the  same 
side,  and  reach  the  brain  as  uncrossed  paths.  Collaterals 
of  the  crossed  and  uncrossed  paths  from  the  nucleus  prob- 
ably reach  the  motor  nuclei  of  the  fifth,  seventh,  ninth, 
and  twelfth  nerves  of  both  sides.  For  reasons  already 
stated  it  is  probable  that  many  of  the  functional  relations 
between  the  cranial  nuclei  are  mainly  established  through 
paths  that  pass  by  way  of  the  cerebellum. 

2.  By  axones  from  the  cells  of  the  fifth  nucleus  that 
enter  the  inferior  peduncle  and  pass  to  the  cerebellum  as 
constituents  of  the  nucleo-cerebellar  tract.  These  paths 
are  mainly  crossed 

3.  By  collaterals  or  stems  of  the  arcuate  paths  with 
the  sensory  nuclei  of  the  fifth,  seventh,  ninth,  and  tenth 
nerves  of  the  opposite  side. 

The  chief  motor  nucleus  of  the  fifth  (nucleus  mastica- 
torius)    is  a  short  column  of  grey  matter  lying  in  the, 


ANATOMY  29 

upper  part  of  the  pons,  close  to  the  median  side  of  the 
sensory  nucleus. 

The  nucleus  consists  of  large  stellate  cells,  the  axones 
of  which  pass  through  the  tegmentum  to  the  surface  of 
the  pons  as  the  motor  fibres  of  the  fifth  nerve.  From  the 
mesial  portion  of  the  nucleus  a  number  of  fibres  pass 
dorsally  in  a  curv^ed  manner  toward  the  raphe,  which  they 
cross  beneath  the  floor  of  the  fourth  ventricle  to  reach  the 
opposite  nucleus.  A  smaller  constituent  of  the  fifth 
motor  root — the  descending  mesencephalic  root — includes 
fibres  that  spring  from  cells  lying  within  the  lateral  part 
of  the  grey  matter  in  and  about  the  Sylvian  aqueduct. 
These  fibres  descend  to  join  the  larger  tract  from  the  chief 
motor  nucleus.  Some  fibres  that  spring  from  the  pig- 
mented cells  of  the  substantia  ferruginea  of  the  same  and 
opposite  side  join  the  descending  mesencephalic  root  of 
the  fifth  ner^^e. 

The  connections  of  the  motor  part  of  the  fifth  nerve 
are: 

1.  With  the  cortex  of  the  lower  third  of  the  prsecen- 
tral  convolution  of  the  o^^posite  side  mainly,  but  to  some 
extent  of  the  same  side.  The  pathway  is  via  the  corona 
radiata,  internal  capsule,  and  cerebral  peduncle  into  the 
pons,  where,  for  the  most  part,  the  fibres  decussate  and 
end  about  the  motor  nucleus.  The  fibres  from  the  cere- 
bral cortex  to  the  cranial  motor  nuclei,  especially  those  to 
the  seventh  and  twelfth,  join  the  fillet,  constituting  what 
is  known  as  the  crustal  fillet.      (See  Fillet.) 

The  seventh  is  now^  considered  a  mixed  ners^e.  The 
cells  of  the  primary  sensory  neurones  of  the  seventh  lie  in 
the  geniculate  ganglion,  situated  in  the  knee  of  the  facial 
canal  and  lying  above  the  eighth  and  below  the  seventh 
nerve.  The  dendrites  of  these  sensory  neurones  constitute 
the  sensor}^  peripheral  fibres  of  the  seventh,  which  course 
in  the  pars  intermedia  or  ner\^e  of  Wrisberg.  The  axones 
of  the  geniculate  neurones  form  the  sensory  root  of  the 
seventh.  The  sensory  nucleus  of  reception  of  the  seventh 
nerve  is  shared  in  common  with  the  ninth  and  tenth 
nerv^es.  The  fibres  of  the  seventh  nerve  on  approaching 
this  nucleus  divide  like  those  of  the  fifth  into  short 
ascending  and  long  descending  branches.  They  terminate 
about  the  neurones  of  the  nucleus,  the  paths  being  con- 


30  SEMICIRCULAR   CANALS 

tinned  by  axones  that  pass  to  the  mesial  fillet  of  the 
opposite  side,  and  eventually  to  the  cerebral  cortex.  The 
afferent  fibres  of  the  seventh  nerve  are  distributed  chiefly 
through  the  chorda  tympani,  which  emerges  from  the 
tympanic  cavity  through  the  Glasserian  fissure,  to  join 
the  lingual  nerve.  They  mediate  sensations  of  taste  from 
the  anterior  two-thirds  of  the  tongue.  As  these  fibres 
end  in  part,  at  least,  in  the  same  nucleus  of  reception  as 
the  ninth  nerve,  they  are  considered  by  some  authors  as 
an  aberrant  x^ortion  of  the  latter.  Because  removal  of  the 
Gasserian  ganglion  has  been  followed  by  complete  loss  of 
taste  in  the  corresponding  side  of  the  tongue  (according 
to  some  surgeons  in  the  anterior  two-thirds  only) ,  it  has 
been  assumed  that  all  the  fibres  of  taste  pass  by  way  of 
the  fifth  nerve,  or  at  least  that  those  fibres  of  taste  run- 
ning in  the  chorda  tympani  Ijelong  in  reality  to  the  fifth 
nerve. 

However,  the  results  of  Cushing,^^  following  removal 
of  the  Gasserian  ganglion,  show  that  in  no  case  was  the 
sense  of  taste  in  the  posterior  third  of  the  tongue  affect- 
ed, whilst  that  of  the  anterior  two-thirds,  though  at  first 
diminished  or  even  lost,  was  subsequently  completely 
restored.  It  seems,  therefore,  that  the  loss  of  taste  fol- 
lowing removal  of  the  Gasserian  ganglion  was  merely  a 
bye-result  of  the  operation.  Gushing  attributes  the  tem- 
porary loss  of  taste  to  post-operative  degeneration  and 
swelling  of  the  fibres  of  the  lingual  nerve,  which  affected 
the  conductivity  of  the  intermingled  fibres  of  the  chorda 
tympani.  The  taste  fibres  of  the  chorda  t3nnpani,  there- 
fore, do  not  originate  in  the  Gasserian  ganglion,  and  the 
opinion  given  above  referring  their  origin  to  the  genicu- 
late ganglion  seems,  if  anything,  to  be  substantiated. 
Hunt'*^  has  shown  that  inflammation  of  the  geniculate 
ganglion  is  accompanied  by  herpes  zoster  of  the  tym- 
panum, external  auditory  canal,  and  concha,  often  accom- 
panied by  peripheral  facial  palsy,  tinnitus,  deafness,  and 
vertigo.  The  latter  symptoms  are  due  to  the  close  rela- 
tions of  the  seventh  and  eighthnerves  within  the  temporal 
bone.  Hunt  farther  pointed  out  the  association  of  in- 
flammations of  the  Gasserian  ganglion  and  the  ganglia  of 
the  second,  third,  and  fourth  dorso-spinal  cervical  ganglia 
with  herpes  of  the  face  and  of  the  occipito-collaris  region 


ANATOMY  81 

respectively,  thus  establishing  the  homology  between  the 
Gasserian  and  geniculate  ganglia  and  those  of  the  dorso- 
spinal  roots.  Head  and  Campbell  ^Uiad  previously  shown 
that  herpes  zoster  was  due  to  a  specific  inflammation  of 
the  dorsal  spinal  root  ganglia. 

The  motor  nucleus  of  the  seventh  nerve  lies  in  the  teg- 
mental region  of  the  pons,  ventral  to  the  sixth  nucleus, 
beneath  the  middle  of  the  fourth  ventricle.  The  connec- 
tions of  this  nucleus  are: 

1.  With  the  motor  cerebral  cortex  of  the  opposite  side 
by  way  of  the  corona  radiata,  internal  capsule,  crus  cere- 
bri, and  the  crustal  fillet.  The  decussation  takes  place 
about  the  level  of  the  nucleus  of  the  j)ons. 

2.  With  the  nucleus  of  the  opposite  side.  This  con- 
nection has  not  been  satisfactorily  demonstrated. 

From  clinical  and  pathological  observations  it  has 
been  assumed  that  a  special  group  of  cells  in  the  nucleus 
is  related  to  the  orbicularis  palpebrarum  and  frontalis 
muscles.  This  group  of  cells  is  closely  associated  with 
the  portion  of  the  third  nucleus  innerv^ating  the  levatores 
palpebrarum,  and  is  bilaterally  represented  in  the  cerebral 
motor  cortex.  Hence  the  absence  of  paralysis  of  volun- 
tary motion  of  the  muscles  that  close  the  eye  in  hemi- 
plegia from  one-sided  cerebral  lesion,  e.g.,  hemorrhage. 

Ferrier  ^  pointed  out  similar  instances  of  bilateral  cor- 
tical innervation  by  way  of  contrast  with  the  one-sided 
cortical  representation  of  speech  in  Broca's  centre. 

The  seventh  nerve  supplies  motor  innervation  to  the 
muscles  of  the  face,  of  part  of  the  scalp,  and  of  the  ear, 
including  its  intrinsic  muscles. 

The  secretory  and  vaso-dilator  fil^res  (bull3ar  autono- 
mics) for  the  submaxillary  and  sublingual  salivary  glands 
pass  by  way  of  the  chorda  t}Tnpani  which,  emerging  from 
the  tympanic  cavity  through  the  Glasserian  fissure,  joins 
the  lingual  nerve.  After  coursing  a  short  distance  with 
this  nerve  the  secretory  and  vaso-dilator  fibres  for  the 
salivary  glands  mentioned,  branch  off  and  pass  to  the 
glands  along  the  ducts  of  the  latter.  The  cells  of  the  so- 
called  submaxillary  ganglion  receive  only  fibres  destined 
for  the  suljlingual  gland,  as  shown  by  Langley,  who  sug- 
gests that  the  ganglion  be  called  the  sublingual.  The 
fibres    to    the    submaxillary    gland    connect  with  nerve 


32  ,        SEMICIRCULAR  CANALS 

cells  lying  within  the  hiliis  of  the  gland;  The  ^yn4-» 
pathetic  autonomics  reach  the  glands  by  way  of  the  supe- 
rior cervical  ganglion. 

The  ninth  is  also  a  mixed  nerve.  The  cells  of  the 
primary  sensory  neurones  lie  in  the  superior  and  petrous 
ganglia  (g.  superius  and  g.  petrosum) ,  situated  upon  the 
upper  part  of  the  nerve  trunk  as  it  emerges  from  the 
skull.  The  sensory  root  traverses  the  formatio  reticularis 
grisea,  and  just  before  reaching  the  dorsal  nucleus  divides 
into  a  mesial  and  a  lateral  bundle  of  fibres.  The  former 
and  smaller  bundle  ends  about  the  cells  of  the  sensory 
part  of  the  dorsal  nucleus  (nuc.  alee  cinerese) .  It  is  sup- 
posed that  the  cells  in  the  upper  part  of  the  nucleus  are 
related  to  the  sense  of  taste,  and  it  is  about  these  cells 
that  the  taste  fibres  of  the  chorda  tympani  end  in  part  at 
least.  The  second  and  larger  bundle  of  fibres  forms  the 
chief  constituent  of  the  fasciculus  solitarius  along  the 
surface  and  l^etween  the  fibres  of  which  lies  a  slender 
column  of  grey  matter.  The  cells  of  this  grey  matter 
constitute  the  spinal  reception  nucleus  of  this  part  of  the 
ninth  nerve. 

The  motor  portion  of  the  ninth  nerve  springs  from 
cells  lying  in  the  dorsal  nucleus  and  in  the  nucleus  am- 
biguus.  It  is  in  relation  with  the  cortex  of  the  lower  part 
of  the  prsecentral  gyrus  of  the  opposite  side.  The  ninth 
nerve  mediates  sensations  from  the  mucous  membrane  of 
the  tongue  and  pharynx  (in  part),  and  from  the  tym- 
panic cavity  and  Eustachian  tube.  It  sends  motor  fibres 
to  the  nuiscles  of  the  pharynx  and  base  of  the  tongue  and 
secretory  fibres  to  the  parotid  gland.  The  dorsal  nucleus, 
which  is  the  nucleus  of  origin  and  reception  for  the  ninth 
and  tenth  nerves,  and  for  the  taste  fibres  of  the  chorda 
tympani  passing  in  the  seventh,  lies  just  lateral  to  the 
median  vestibular  and  upper  part  of  the  twelfth  nucleus. 
Its  upper  portion  is  covered  })y  the  spinal  vestibular 
nucleus  and  its  lower  portion  overlies  the  twelfth  nucleus. 
The  middle  portion  of  the  nucleus — the  fovea  vagi — is 
in  intimate  relation  with  the  floor  of  the  fourth  ventricle. 
The  median  portion  of  the  nucleus  constitutes  the  dorsal 
motor  nucleus  and  the  remaining  portion  the  dorsal  sen- 
sory nucleus.  The  nucleus  ambiguus  (nucleus  ventral  is) 
lies  in  the  formatio  reticularis  grisea,  midway  between 


ANATOMY  S^ 

the  substantia  gelatinosa  and  the  dorsal  accessory  olivary 
nucleus.  It  consists  of  a  small  group  of  cells,  giving 
origin  to  motor  fibres,  which  unite  with  the  fibres  from 
the  dorsal  motor  nucleus.  The  motor  nuclei  of  the  ninth 
are  in  crossed  relation  with  the  cerebral  cortex,  like  the 
other  cranial  motor  nerves. 

The  sensory  part  of  the  dorsal  nucleus  (nuc.  alse 
cinereae)  and  the  spinal  nucleus  (nuc.  tractus  solitarii) , 
which  resembles  the  corresponding  nucleus  of  the  fifth 
nerve,  are  reception  nuclei  for  the  lateral  mixed  nerves 
(VII,  IX,  and  X).  The  fasciculus  solitarius  extends 
from  the  upper  border  of  the  medulla  to  the  lower  limit  of 
the  decussation  of  the  fillet,  and  is  related  to  the  sensory 
fibres  of  the  seventh,  ninth,  and  tenth  nerves.  The 
largest  part  of  this  tract  consists  of  the  root  fibres  of  the 
ninth  nerve ;  in  fact,  the  tract  itself  is  in  reality  only  the 
continuation  of  the  larger  bundle  of  fibres  of  the  ninth 
nerve  on  its  way  to  join  its  nucleus  of  reception,  the  lat- 
ter consising  of  cells  lying  upon  and  within  the  fasciculus 
solitarius. 

The  tenth  (vagus,  pneumogastricus)  is  a  mixed  nerve. 
The  cell  bodies  of  the  primary  sensory  neurones  of  the 
vagus  lie  within  the  ganglion  of  the  root  in  the  jugular 
foramen  and  the  ganglion  of  the  trunk  outside  the  jugular 
foramen,  both  ganglia  being  situated  upon  the  upper 
part  of  the  nerve. 

The  centrally  directed  processes  pass  into  the  medulla 
in  company  with  the  motor  strands,  and  divide  into  two 
sets  of  fibres,  of  which  the  larger  set  ends  about  the  lower 
portion  of  the  dorsal  sensory  nucleus,  whilst  the  smaller 
set  bends  downward  and  enters  the  fasciculus  solitarius  to 
end  about  the  cells  of  the  reception  nucleus,  situated  upon 
and  between  the  fibres  of  the  fasciculus.  The  sensory 
fibres,  therefore,  of  the  ninth  and  tenth  nerves,  as  well  as 
part,  at  least,  of  the  seventh  (chorda  tympani  fibres)  have 
a  more  or  less  common  nucleus  of  reception  in  the  sen- 
sory part  of  the  dorsal  nucleus  (nuc.  alae  cinereae)  and  in 
the  spinal  reception  nucleus  of  the  fasciculus  solitarius 
(nuc.  tractus  solitarii). 

The  central  connections  of  the  vagus,  like  those  of  the 
other  mixed  nerves,  include : 

1.  Fibres  to  the  median  fillet,  chiefly  of  the  opposite 


34  SEMICIRCULAR   CANALS 

side,  which  pass  to  the  optic  thalamus.  From  the  latter 
they  are  relayed  to  the  cerebral  cortex. 

2.  Fibres  that  pass  to  the  cerebellum,  mainly  of  the 
opposite  side,  as  part  of  the  nucleo-cerebellar  tract. 
Ross^'^  considered  the  cells  of  the  sensory  part  of  the 
Tagus  as  the  analogues  of  the  vesicular  cells  of  Clarke's 
column. 

8.  Fibres  to  various  other  nuclei  and  centres  in  the 
medulla,  such  as  the  vaso-motor  and  respiratory  centres. 

The  sensory  portion  of  the  vagus  mediates  sensation 
from  the  mucous  membrane  of  the  pharynx  (branch  from 
the  ganglion  of  the  trunk),  larynx,  trachea,  oesophagus, 
stomach,  intestines,  gall-bladder,  gall-ducts,  and  from 
the  lungs  and  pericardium.  The  auricular  branch  from 
the  ganglion  of  the  root  supplies  the  skin  of  the  posterior 
portion  of  the  auricle  and  the  posterior  inferior  portion  of 
the  external  auditory  canal. 

Besides  the  above  there  are  special  fibres  to  the  heart, 
liver,  spleen,  pancreas,  kidneys,  adrenals,  and  possibly  to 
the  intestinal  blood-vessels. 

The  bulbar  or  accessory  portion  of  the  eleventh  nerve  is 
generally  admitted  to  be  an  integral  part  of  the  motor 
division  of  the  tenth.  It  is  still  a  question  as  to  the 
ultimate  distribution  of  these  fibres  as  well  as  to  that  of 
some  of  the  motor  fibres  of  the  tenth  nerve  proper. 

Van  Gehucten  ^^  believes  that  the  accessory  fibres  are 
distributed  chiefly  to  the  larynx  via  the  inferior  laryngeal 
nerve,  a  branch  of  the  tenth,  and  do  not  reach  the  heart 
or  stomach.  Brunton^^  concluded  that  the  inhibitory 
cardiac  fibres  originate  in  the  accessory  nucleus.  The 
efferent  fibres  to  the  heart  from  the  tenth  nerve  proper  are 
most  probably  inhibitory,  and  it  is  still  a  question 
whether  they  reach  the  heart  muscle  directly  or  end  about 
neurones  within  the  heart  structure. 

The  efferent  fil^res  of  the  tenth  to  the  stomach  and 
intestines  include  motor,  inhibitory,  and  secretory  fibres. 
It  is  stated  that  some  of  the  fibres  affect  the  calibre  of  the 
blood-vessels  of  the  stomach  and  liver,  but  Burton-Opitz  ^^ 
has  si  1  own  that  no  vaso-motors  for  the  stomach  or  liver 
run  in  the  pneumogastric  nerve.  The  motor  fibres  of  the 
tenth  nerve  originate  in  the  cells  of  the  motor  portion  of 
the  dorsal  nucleus,  and  in  those  of  the  nucleus  ambiguus, 


ANATOMY  35 

more  or  less  in  common  with  the  motor  fibres  of  the  ninth 
nerve.  The  accessory  fibres  spring  from  cells  located 
within  the  nucleus  ambiguus  only.  The  fibres  from  the 
nucleus  ambiguus  at  first  pass  backward  toward  the  floor 
of  the  fourth  ventricle,  and  then  bend  sharply  outward, 
and  become  condensed  into  compact  strands  that  receive 
motor  fibres  from  the  dorsal  nucleus.  From  this  point 
they  proceed  ventro-laterally  with  the  sensory  fibres  to  the 
superficial  origin  of  the  nerve. 

The  eleventh  or  accessory  nerve  is  a  purely  motor  nerve 
supplying  the  sterno-mastoid  and  trapezius  muscles.  Its 
upper  medullary  roots  spring  from  the  cells  of  the  motor 
portion  of  the  dorsal  nucleus,  which  gives  origin  to  the 
vagus,  whilst  its  lower,  spinal  roots  spring  from  the 
anterior  horn  of  the  grey  matter  of  the  cord,  as  low  as  the 
fifth  or  seventh  segment.  The  relation  of  the  upper  por- 
tion of  this  nerve  to  the  vagus,  of  which  it  is  considered 
to  be  a  part,  has  already  been  discussed. 

The  twelfth  or  hypoglossal  is  also  a  pure  motor  nerve 
supplying  the  muscles  of  the  tongue,  the  extrinsic  mus- 
cles of  the  lar}mx,  and  those  attached  to  the  hyoid  bone. 
Its  fibres  originate  in  a  distinct  nucleus  lying  in  the  floor 
of  the  fourth  ventricle  near  the  middle  line. 

The  eleventh  and  twelfth  nerves,  like  the  other  motor 
cranial  nerves,  are  related  to  the  cerebral  cortex  of  the 
opposite  side.  They  are  also  related  to  the  other  cranial 
nuclei  to  some  extent  through  the  cerebellum.  It  is  stated 
that  the  third,  seventh,  and  twelfth  nuclei  are  in  intimate 
relation.  The  objections  urged  against  the  simple  direct  re- 
lations between  the  cranial  nuclei  render  it  probable  that 
the  chief  relation  between  these  three  nuclei  is  an  indirect 
one  through  the  medium  of  a  common  coordinating  centre, 
such  as  the  cerebellum. 

Gaskell  ^^  has  shown  that  every  spinal  segment  has  a 
somatic  and  a  splanchnic  root.  Each  somatic  root  is 
divided  into  a  ganglionated  and  a  non-ganglionated  por- 
tion springing  from  the  cells  of  the  posterior  (dorsal- 
spinal-root  ganglion)  and  anterior  horns  respectively. 
The  splanchnic  root  is  also  divided  into  ganglionated  and 
non-ganglionated  portions,  which  spring  from  the  cells 
of  the  lateral  horn  and  those  of  Clarke's  column  respect- 
ively.    The  ganglia  of  the  splanchnic  root  are  the  ganglia 


36  SEMICIRCULAR  CANALS 

of  the  sympathetic  chain,  and  are  the  homologues  of  the 
ganglion  trunci  vagi.  Thus  in  the  eleventh  nerve  the 
somatic  root,  besides  sending  a  branch  to  the  cervical 
plexus,  is  distributed  to  the  sterno-mastoid  and  trapezius 
muscles,  whilst  the  splanchnic  root  from  the  lateral  horn 
is  distributed  to  the  viscera. 


CHAPTER  IV 

BLOOD-SUPPLY   OF   THE    LABYRINTH   AND    OF    THE 
CRANIAL   NUCLEI 

The  labyrinth  is  supplied  by  the  internal  auditory 
artery,  a  branch  of  the  basilar,  which  accompanies  the 
auditory  nerve.  This  vessel  supplies  the  vestibule,  semi- 
circular canals,  cochlea,  and  their  membranous  contents. 
The  internal  auditory  divides  into  the  common  cochlear 
(Siebenmann)  and  the  internal  vestibular  artery.  The 
latter  vessel  supplies  the  vestibule.  The  former  divides 
into  two  branches,  one  of  which,  the  cochlear  artery 
proper,  supplies  the  two  superior  spirals  of  the  cochlea, 
whilst  the  other — the  vestibulo-cochlear  artery — supplies 
the  inferior  spiral  of  the  cochlea  and  the  vestibule.  The 
blood  is  returned  by  the  internal  auditory  vein  into  the 
superior  petrosal  sinus,  and  by  small  veins  which  pass 
through  the  cochlear  and  vestibular  aqueducts  to  the 
inferior  and  superior  petrosal  sinuses.  Siebenmann 
found  that  the  veins  from  all  the  semicircular  canals 
united  in  a  common  trunk,  which  leaves  the  labyrinth 
along  the  aquseductus  vestibuli ;  but  Shambaugh  ^  found 
that  in  the  sheep,  calf,  and  pig  the  venous  blood  from 
the  vestibule  and  semicircular  canals  drained  into  the 
canaliculi  cochleae,  but  that  in  the  calf  the  vein  from  the 
crus  commune  often  leaves  the  labyrinth  along  the  aquse- 
ductus  vestibuli. 

The  labyrinthine  artery  is  thus  a  part  of  the  central 
brain  system,  and  susceptible  of  similar  pathological 
changes. 

The  branches  to  the  cochlea,  vestibule,  and  semicircu- 
lar canals  form  delicate  convolutions  in  intimate  relation 
with  the  cochlear  and  vestibular  nerve  elements.  Wit- 
maack,^^  discussing  the  causation  of  senile  deafness, 
attributes  the  latter  to  disturbed  nutrition  of  the  cochlear 

37 


38  SEMICIRCULAR  CANALS 

nen^e,  caused  byarterio-sclerosis.  The  "elective  vulnera- 
bility" of  the  cochlear  branch  of  the  auditory  nerve  is 
due,  in  part,  to  the  fact  that  this  nerve  is  imbedded  in  a 
bony  capsule,  partly  surrounded  by  broad,  lymphatic 
spaces.  The  blood-vessels  are  end  arteries,  whilst  the 
ganglion  cells  of  the  cochlear  ganglion  are  bipolar,  and 
are  much  smaller  than  all  other  ganglion  cells  found  in 
vertebrates. 

The  vessels  of  the  labyrinth  are  not  affected  by  intra- 
cranial pressure  like  those  of  the  retina,  because  most  of 
the  venous  blood  and  lymph  passes  from  the  aquseductus 
cochleae  into  the  jugular  vein.  In  conditions  like  tumor 
of  the  brain  the  ear  presents  no  sign  analogous  to  the 
retinal  choked  disc. 

The  region  of  the  third  nucleus  is  supplied  by  small 
delicate  branches  of  the  posterior  cerebral  artery.  These 
branches  are  end  arteries;  that  is,  they  form  no  anasto- 
moses, and  have  no  communication  with  the  vascular  sys- 
tem of  bordering  regions.  Moreover,  these  branches 
change  from  a  horizontal  to  a  vertical  course,  and  they, 
as  well  as  the  superior  and  middle  cerebellar  arteries 
(branches  of  the  basilar)  originate  at  a  point  where  the 
carotid  and  basilar  blood-streams  meet.  These  facts 
have  been  adduced  to  explain  the  momentary  nystagmus, 
vertigo  and  disturbances  of  vision  which  attend  sudden 
stooping  and  rising  to  the  erect  position,  the  chief  factor 
in  the  causation  of  these  symptoms  being  sudden  altera- 
tion in  the  blood-supply  of  the  ocular,  cerebellar,  and  other 
centres. 

The  pons  and  medulla  are  supplied  by  the  vertebral 
arteries  and  by  branches  springing  from  them,  viz. ,  the 
basilar  and  anterior  si)inal.  The  latter  supplies  the 
medulla  oblongata  and  the  nuclei  situated  in  its  lower 
region,  including  the  eleventh  and  twelfth.  The  fifth, 
sixth,  and  seventh  nuclei  are  supplied  by  branches  of  the 
basilar.  The  medulla  oblongata  receives  further  blood- 
supply  from  branches  of  the  dorsal  spinal,  posterior  cere- 
bral, and  inferior  and  posterior  cerebellar  arteries.  The 
central  artf^ry  of  the  medulla,  a  branch  of  the  basilar, 
sends  delicate  branches  to  the  cochlear  and  vestibular 
nuclei.  A  branch  of  the  posterior  communicating  artery 
furnishes  a  terminal  to  the  red  nucleus.     The  vermis  of 


ANATOMY  39 

the  cerebellum  receives  a  branch  from  the  superior  cere- 
bellar artery,  whilst  the  nucleus  dentatus  is  supplied  by  a 
branch  from  the  middle  cerebellar.  The  cerebral  peduncle, 
through  which  pass  the  bulbo-cerebral  and  cerebello-cere- 
bral  paths  receives  branches  from  the  posterior  cerebral 
arteries.  Branches  from  the  posterior  communicating 
and  from  the  anterior  choroid  arteries  reach  the  internal 
capsule. 

It  is  stated  (Kyle  ^')  that  affections  tending  to  obstruct 
the  vessels  supplying  the  cortical  centres  and  the  nuclei 
and  paths  related  to  the  vestibular  system  may  cause  ver- 
tigo and  other  sjmiptoms  usually  referred  to  disturbances 
within  the  labyrinth. 

In  general,  it  may  be  said  that  the  vascular  supply  of 
the  base  of  the  brain  is  faulty  from  the  standpoint  of 
collateral  circulation.  Hence  the  persistence  of  sjmiptoms 
from  small  vascular  lesions  of  areas  adjoining  the  base, 
lesions  which,  if  they  occurred  upon  the  convexity  of  the 
hemispheres,  would  easily  be  compensated  by  collateral 
blood-supply.  The  area  of  the  third  nucleus  having  the 
poorest  blood-supply  of  any  part  of  the  brain,  every 
serious  disturbance  of  the  circulation  has  its  effect  upon 
the  innervation  of  the  ocular  muscles.  Thus  in  profound 
anaemic  states  from  loss  of  blood  or  other  cause,  and  in 
the  cachexia  of  wasting  diseases,  it  is  common  to  find 
disturbances  of  vision,  some  nystagmus,  and  vertigo. 
These  symptoms  are  similarly  encountered  when  a  person 
who  has  lain  in  bed  some  time  first  assumes  the  erect 
posture.  Here  the  vaso-motor  mechanisms  have  become 
disordered  from  disuse,  and  there  ensue,  when  the  patient 
first  attempts  to  stand  up,  temporary, irregularities  in  the 
blood-supply  of  the  ocular  and  possibly  other  centres. 


CHAPTER  V 

SYNOPSIS    OF   ANATOMICAL   CONNECTIONS 

Co7inections  of  the   Vestibular  Nerve 

The  vestibular  nerve  ends  in  the  vestibular  nuclei  of 
reception.     From  the  nuclei  fibres  pass : 

(a)  To  the  cerebellar  roof  nucleus  of  the  opposite  side 
as  the  vestibulo-cerebellar  tract.  Risien-Russell  ^^  and 
Ferrier  and  Turner  ^  showed  that  this  is  an  efferent  path 
between  the  vermis  and  Deiters'  nucleus,  but  Kolliker, 
from  embryological  studies,  concludes  that  some  of  the 
fibres  are  axones  of  Deiters'  cells  a  few  coming  from  the 
chief  auditory  nucleus. 

(b)  As  arcuate  fibres  passing  ventro-medially  into  the 
tegmentum  of  the  pons  to  cross  the  middle  line,  and  so 
bend  upward  and  downward  to  reach  other  levels.  Some 
fibres,  however,  remain  on  the  same  side.  Of  the  crossed 
fibres  some  are  said  to  join  the  mesial  fillet  to  reach  the 
thalamus  and  superior  colliculi,  while  others  are  said  to 
join  the  lateral  fillet  and  so  reach  the  inferior  colliculi, 
and  possibly  the  auditory  cortex. 

(c)  Commissural  fibres  between  the  nucleus  of  Bech- 
terew  or  superior  vestibular  nucleus  on  either  side. 

(d)  Fibres  to  the  abducent  nucleus.  Gordinier  and 
others  believe  that  each  vestibular  nucleus  sends  fibres  to 
the  abducent  nucleus  on  either  side.  Duval  and  Laborde 
showed  that  the  sixth  nucleus  was  connected  with  the 
third  and  fourth  nerve  nuclei  of  the  opposite  side,  and 
stimulation  of  the  area  of  the  sixth  nucleus  caused  the 
eyes  tcj  turn  to  the  side  of  stimulation.  This,  however, 
does  not  prove  that  the  sixth  nucleus  coordinates  these 
movements.  Schafer  insists  that  no  fibres  enter  the  pos- 
terior longitudinal  fasciculus  from  the  sixth  or  third 
nucleus.  Moreover,  it  is  not  apparent  why  the  fibres  to 
the  sixth  nucleus  are  necessarily  the  direct  continuations 

40 


ANATOMY  41 

of  vestibular  fibre-paths,  and  not  the  continuation  of 
descending  paths  from  the  cerebellum.  The  posterior 
longitudinal  fasciculus  is  in  intimate  relation  with  the 
nuclei  of  the  sixth,  third,  and  fourth  nerves,  and  receives 
numerous  fibres,  both  crossed  and  uncrossed,  from  the 
vestibular  (including  Deiters')  and  from  other  nuclei. 
Moreover,  when  eye  movements  take  place  in  response  to 
vestibular  stimulation  movements  of  other  parts  take 
place  concurrently  and  in  a  coordinated  manner.  Hence 
but  little  importance  is  to  be  attached  to  this  connection 
between  the  vestibular  nerve  and  the  sixth  nucleus,  unless 
it  be  distinctly  understood  as  an  indirect  connection 
through  the  medium  of  the  cerebellum  or  other  coordina- 
ting centre  via  the  vestibular  (Deiters')  nucleus  or  the 
posterior  longitudinal  fasciculus,  or  both. 

(e)  Crossed  and  uncrossed  fibres  to  the  posterior 
longitudinal  fasciculus. 

(f)  Fibres  to  the  spinal  cord.  These  fibres  com- 
municate with  the  olivary  body  and  lateral  columns. 
The  descending  vestibulo-olivary  tract  passes  to  the 
olivary  body  of  the  same  side  (Van  Giesen  ^^) ,  whilst  the 
vestibulo- spinal  tract  passes  through  the  periphery  of  the 
lateral  field  of  the  formatio  reticularis,  and  descends  in 
the  lateral  column  of  the  cord.  Its  ultimate  distribution 
is  unknown,  but  it  probably  ends  in  relation  with  the 
ventral  horn  cells. 

The  fibres  to  the  spinal  cord  and  superior  olive  are 
not  altogether  to  be  considered  as  mainly  continuations  of 
paths  direct  from  the  vestibular  nerve.  For  the  reasons 
given  in  discussing  the  fibres  to  the  sixth  nucleus  these 
fibres  are  to  be  regarded  as  coming  in  part  from  the  cere- 
bellum via  Deiters'  nucleus.  The  latter  has  many  affer- 
ent and  efferent  neurones,  and  is,  therefore,  properly  con- 
sidered as  a  relay  station  for  both  afferent  and  efferent 
impulses,  rather  than  a  coordinating  centre  of  the  higher 
order.  More  recent  investigations  show  that  part  of  the 
ventral  (anterior)  marginal  fasciculus  (vestibulo-spinal 
tract)  comes  from  the  roof  nucleus  of  the  cerebellmn 
(Morris  ^^) .  The  same  author  states  that  the  fibres  from 
the  vestibular  nucleus  to  the  abducent  nucleus  travel  by 
way  of  the  posterior  median  (longitudinal)  fasciculus  of 
both  sides. 


42  SEMICIRCULAR   CANALS 

The  vestibulo-olivary  tract  is  best  regarded  as  being 
in  part  at  least  the  continuation  of  vestibular  paths  after 
interruption  in  Deiters'  nucleus.  Reaching  the  olive  on 
the  same  side  the  fibres  cross  to  the  opposite  olive  and 
proceed  in  part  to  the  cerebellum  by  way  of  the  restiform 
body.  This  view  seems  to  be  supported  by  v.  Bech- 
terew's  experiments,  in  which  lesions  of  the  inferior  olive 
caused  rotations  and  ocular  deviations,  exactly  like  those 
following  section  of  the  vestibular  nerve  on  the  same 
side.  The  tract  may,  therefore,  be  called  the  crossed 
vestibulo-olivo-cerebellar  tract,  whilst  the  descending  ves- 
tibulo-spinal  tract  may  be  called  the  cerebello-vestibulo- 
spinal  tract.  The  olivary  fasciculus,  or  Helweg's  bundle, 
connects  the  spinal  neurones  with  the  olive  and  indirectly 
with  the  cerebellum  (Morris). 

Much  confusion  is  created  by  anatomical  writers 
retaining  the  term,  "direct  sensory  cerebellar  tract  of 
Edinger. "  This  tract  was  described  by  Edinger  in  his 
earlier  work,  viz.,  "Twelve  Lectures  on  the  Structure  of 
the  Central  Nervous  System."  In  his  later  work,  "The 
Anatomy  of  the  Central  Nervous  System  of  Man  and  of 
the  Vertebrates  in  General,"  Edinger  himself  discards  the 
term,  "direct  sensory  cerebellar  tract,"  saying:  "It  is 
wiser  at  present  to  designate  the  system  as  tractus  cere- 
bellaris  acustica,  etc."  We  may,  therefore,  conclude 
that  the  direct  sensory  cerebellar  tract  contains  nothing 
more  by  way  of  afferent  paths  than  what  is  included  in 
the  sensory  nucleo-cerebellar  paths  (q.v.). 

According  to  Cunningham, ^^  botli  the  principal  nucleus 
and  the  nucleus  of  Deiters  are  in  intimate  relation  with 
the  superior  worm  of  the  cerebellum.  Deiters  himself,  as 
well  as  Ferrier  and  Turner,  believe  that  Deiters'  nucleus 
is  an  internode  between  the  cerebellum  and  the  cord. 
Ferrier  and  Turner  adduce  strong  evidence  to  support  this 
view.  But  Kolliker  has  shown  that  some  of  the  paths 
are  afferent,  i.e.,  to  the  cerebellum.  Klemoff^  believes 
the  axones  of  Dieters'  nucleus  form  the  ventral  (anterior) 
tract  of  Lowenthal,  i.e.,  the  tractus  vestibulo-spinalis  of 
Monakow,  descending  in  the  anterolateral  column  of  the 
cord. 

Ferrier  and  Turner  observed  that  after  section  of  the 
eighth   nerve,    the   descending   vestibular   root   did   not 


ANATOMY  43 

degenerate.  They  believe,  therefore,  that  this  root  forms 
an  internodal  connection  between  Deiters'  nucleus  and  the 
cuneate  nucleus.  Bnice  saw  the  lower  end  of  the  descend- 
ing vestibular  root  terminate  in  the  cuneate  nucleus.  It 
seems  probable,  therefore,  that  the  descending  vestibular 
root  is  a  continuation  of  afferent  cerebellar  paths  repre- 
sented in  the  dorsal  fasciculi  (columns  of  Goll  and 
Burdach) . 

Cerebellar  Connections 

1.   Through  the  inferior  peduncle  by: 

(a)  The  direct  cerebellar  tract  (dorsal  spino-cerebel- 
lar  fasciculus  or  tract  of  Flechsig)  continues,  after  in- 
terruption, the  afferent  paths  from  the  posterior  nerve 
roots  of  the  same  side  to  the  superior  worm  of  the  same 
and  opposite  side,  i.e.,  in  the  monticulate  and  lingual 
lobules. 

(b)  The  arcuate  fibres — anterior  and  posterior  super- 
ficial— from  the  gracile  and  cuneate  nuclei  of  the  same 
and  opposite  side.  The  fibres  of  the  so-called  descending 
root  of  the  vestibular  nerve  may  be  grouped  here.  (See 
Vestibular  connections.) 

(c)  The  olivo- cerebellar  fibres,  chiefly  from  the  oppo- 
site inferior  olivary  nucleus,  but  to  a  limited  extent  from 
the  nucleus  of  the  same  side.  These  constitute  the  bulk 
of  the  latter  part  of  the  restiform  body,  and  end  within 
the  cortex  of  the  hemisphere  and  worm,  and  also  within 
the  fibre  complex  enveloping  the  nucleus  dentatus.  The 
fibres  are  mostly  afferent  (v.  Bechterew  ^^) .  The  atrophy, 
however,  of  this  nucleus,  which  is  jDresent  in  failure  of 
development  of  the  opposite  half  of  the  cerebellum  or  fol- 
lowing its  removal,  seems  to  show  that  many  of  the  cere- 
bello-olivary  fibres  are  efferent  paths.  The  further  links 
of  connection  are  uncertain. 

Kolliker  maintains  that  some  of  the  olivo-cerebellar 
fibres  are  axones  of  the  cells  of  Purkinje  from  the  oppo- 
site side,  and  that  fibres  from  some  olivary  cells  pass 
downward  into  the  anterior  ground  bundle.  The  possi- 
bility of  some  of  the  olivo-cerebellar  fibres  being  continu- 
ations of  vestibular  afferent  paths  should  be  remembered. 
The  route  in  such  a  case  would  be  along  the  vestibular 
nerve  to  Deiters'  nucleus,  thence  to  the  olive  on  the  same 


44-  SEMICIRCULAR   CANALS 

side,  thence  cross  the  midline  to  the  opposite  olive  and 
through  the  rest i form  body  to  the  cerebellum.  Such  a 
connection  would  explain  the  phenomena  observed  by  v. 
Bechterew  ^^  following  destruction  of  the  olive  and  many 
other  experimental  phenomena  which  otherwise  are  not 
readily  explicable. 

From  the  manifestly  important  connections  between 
the  olive  and  the  cerebellum  it  would  seem  that  the  olive 
is  a  great  relay  station  for  afferent  and  efferent  cerebellar 
paths,  if  not  a  coordinating  centre  of  equilibrium  on  its 
o^Mi  account,  v.  Bechterew  believes  the  inferior  olive  is 
related  closely  to  tactile  sensibility. 

(d)  Fibres  from  the  nucleus  lateralis  of  the  medulla 
to  the  cortex  of  the  cerebellar  hemisphere.  The  nucleus 
lateralis  is  a  collection  of  cells  in  the  formatio  reticularis 
grisea  near  the  periphery  and  ventral  to  the  spinal 
trigeminal  root.  The  nucleus  is  regarded  as  the  analogue 
of  the  lateral  horn  cells. 

(e)  Fibres  from  the  arcuate  nucleus  (a  collection  of 
cells  in  the  paths  of  the  anterior  superficial  arcuate  fibres) 
to  the  cerebellar  cortex. 

(f)  The  nucleo-cerebellar  tract,  i.e.,  fibres  from  the 
reception  nuclei  of  the  trifacial,  facial,  vestibular,  coch- 
lear, glosso-pharyngeal,  and  vagus.  This  tract  occupies 
the  middle  of  the  peduncle,  and  ends  chiefly  in  the  roof 
nucleus  (nucleus  fastigii)  of  the  same  and  opposite  side. 
This  tract  includes  the  direct  sensory  cerebellar  tract  of 
Edinger.      (See  Vestibular  connections.) 

(g)  Fibres  from  the  cerebellar  roof  nucleus  to  Deiters' 
nucleus,  and  thence  by  tlie  vestibulo-spinal  tract  to  the 
antoro-lateral  column  of  the  cord  (ventral  marginal  fasci- 
culus and  the  fasciculus  from  the  formatio  reticularis). 

(h)  According  to  some  anatomical  writers,  additional 
vestibular,  and  possi})ly  other  sensory  fibres,  pass  with- 
out intf3rruption  byway  of  the  restiform  body  to  the  cere- 
bellar roof  nuclei,  constituting  the  direct  sensory  cere- 
bellar tract  of  Edinger.  As  before  noted,  Edinger's  direct 
sensory  cerebellar  tract,  considered  as  an  afferent  cerebel- 
lar pathway,  is  in  reality  identical  with  the  nucleo- 
cerebellar  tract. 


ANATOMY  45 

Connections  of  tlie  Cerebellum  Through  the  Middle 

Peduncle 

Afferent  paths,  i.e.,  to  the  cerebellum. 

1.  Fibres  from  the  cells  of  the  pontine  nucleus  as  con- 
tinuations of  the  fronto-cerebellar  and  of  the  temporo- 
occipito-cerebellar  tracts.  These  paths  connect  the  cells 
of  the  frontal,  temporal,  and  occipital  lobes  with  the  cor- 
tex of  the  opposite  half  of  the  cerebellum,  ending  chiefly 
in  the  cortex  of  the  hemisphere,  in  the  worm,  and  pos- 
sibly in  the  nucleus  dentatus.  The  tracts  are  chiefly 
crossed. 

2.  Collaterals  from  ]3yramidal  tracts  to  the  pontine 
nuclei. 

Efferent  paths,  i.e.,  from  the  cerebellum. 

1.  Fibres — the  axones  of  the  Purkinje  cells  in  the 
cerebellar  cortex — which  cross  the  middle  line  to  end  in 
relation  with  the  cells  of  the  nucleus  tegmenti  (red 
nucleus) ,  close  to  the  raphe  (v.  Bechterew  ^^) .  The  tract 
is  mainly  uncrossed,  owing  to  a  double  decussation,  viz., 
in  the  superior  peduncles  and  in  Forel's  decussation. 

2.  Fibres  from  the  cells  of  Purkinje  to  the  nucleus 
pontis  of  the  same  and  opposite  side  have  been  assumed 
to  exist.  Ferrier  maintains  that  the  cerebello-pontine 
fibres  of  the  middle  peduncle,  after  crossing  the  middle 
line,  join  the  pyramidal  tract,  to  recross  in  the  pyramidal 
decussation.  Such  a  pathway  would  establish  efferent 
relations  between  each  half  of  the  cerebellum  and  the 
structures  of  the  same  side  of  the  body.  Ferrier 's  experi- 
ments undoubtedly  establish  a  marked  functional  relation- 
ship between  these  parts,  but  recent  observations  seem  to 
show  that  the  efferent  cerebello-pontine  fibres  do  not  end 
in  the  nucleus  pontis  but,  after  crossing  the  middle  line, 
are  believed  to  end  within  the  tegmentum  in  the  red 
nucleus  (v.  Bechterew). 

Ferrier,  however,  makes  no  mention  of  the  nucleus 
pontis,  nor  of  interruption  of  the  efferent  paths  at  this 
point.  V.  Bechterew 's  assumption  may  be  accepted,  and 
there  is  still  provision  for  a  possible  recrossing  of  this 
efferent  cerebellar  path  by  fibres  which  emerge  from  the 
ventro-medial  surface  of  the  red  nucleus,  and  cross  the 


46  SEMICIKCULAR  CANALS 

middle  line  as  the  decussation  of  Forel  bending  down- 
ward as  the  rubro-spinal  tract. 

The  middle  cerebellar  peduncle,  according  to  v.  Bech- 
terew,  contains:  (a)  Cerebral  fibres  which  originate  in 
the  superior  and  lateral  parts  of  the  cerebellar  cortex,  and 
in  the  area  of  the  upper  worm  and  central  nucleus,  and 
pass  to  the  upper  half  of  the  pons,  where  some  of  the  fibres 
from  the  cerebrum  along  the  medial  and  lateral  divisions 
of  the  cerebellar  peduncles  are  interrupted.  The  motor 
tracts  of  the  cerebrum  are  joined  m  the  ganglia  of  the 
pons  by  impulses  from  the  cerebellum  conveyed  in  the 
middle  peduncle. 

(b)  The  spinal  fibres,  which  are  cerebello-fugal,  arise 
from  the  anterior  and  middle  parts  of  the  cerebellar  cor- 
tex, and  end  in  the  grey  matter  of  the  lower  half  of  the 
pons  on  both  sides.  From  this  point  fibres  pass  as  the 
fasciculus  verticalis  to  the  region  of  the  nucleus  reticu- 
laris and  the  lateral  area  of  the  formatio  reticularis,  and 
finally  to  the  antero-lateral  ground  bundles  of  the  cord 
(fasciculus  to  and  from  the  formatio  reticularis) .  A  few 
fibres  reach  the  corpora  quadrigemina  with  the  lemniscus. 
From  the  above  it  is  manifest  that  v.  Bechterew  agrees 
with  Ferrier  in  the  main  facts. 

2.  Fibres  to  the  corpora  quadrigemina  via  the  spinal 
bundle  and  the  median  fillet  (v.  Bechterew) . 

Connections  of  the  Cerehellum  Through  the  Superior 

Peduncle 

Afferent  imths,  i.e.,  to  the  cerebellum. 

1.  Fibres  from  Gowers'  tract  (ventral  spino-cerebellar 
tract),  arching  over  the  fifth  nerve  to  reach  the  superior 
peduncle  and  thence  to  reach  the  dentate  nucleus  and 
cerebellar  cortex  of  the  same  side  (Hoche).  As  some  of 
the  posterior  root  fibres,  of  which  Gowers'  tract  is  a  con- 
tinuation, decussate  in  the  anterior  commissure,  this  tract 
is,  in  part,  crossed. 

Mott  believes  the  fibres  of  Gowers'  tract  taking  this 
course  end  in  the  posterior  portion  of  the  vermis,  whilst 
the  remaining  fibres  of  Gowers'  tract  end  in  the  corpora 
quadrigemina  and  the  thalamus. 


ANATOMY  47 

2.  Fibres  from  the  red  nucleus  to  the  dentate  nucleus. 
This  path  is  mainly  crossed. 

8.  Fibres  to  the  cerebellum  from  the  oculo-motor 
nucleus — afferent  ocular  and  pupillary  paths  (v.  Bech- 
terew).     This  path  is  crossed. 

Efferent  paths,  i.e.,  from  the  cerebellum. 

1.  Fibres  of  the  cerebello-tegmental  tract,  which 
spring  from  the  dentate  nucleus  with  probably  augmenta- 
tions from  the  roof  nucleus  and  cortex  of  the  worm.  At 
the  decussation  of  the  superior  peduncles  most  of  the 
fibres  cross.  Above  this  decussation  the  fibres  are  in 
large  measure  interrupted  in  the  red  nucleus,  those  not  so 
interrupted  passing  through  the  subthalamic  region  to 
end  in  relation  with  the  cells  of  the  thalamus.  Most  of 
the  fibre-paths  ending  in  the  red  nucleus  are  continued  by 
rubral  neurones  to  the  thalamus.  From  the  thalamus  the 
uninterrupted  paths,  as  well  as  those  interrupted  in  the 
red  nucleus,  are  continued  to  the  cerebral  cortex  by  the 
thalamo-cortical  paths.  Many  of  the  fibre-paths  ending 
in  the  red  nucleus  are,  however,  diverted  into  the  rubro- 
spinal tract  which,  for  the  most  part,  crosses  the  median 
line  in  the  decussation  of  Forel,  and  traverses  the  brain 
stem  and  antero-lateral  columns  of  the  cord  to  reach  the 
ventral  root  cells.  The  connections  of  the  cerebellum 
through  the  rubro-spinal  tract  are,  therefore,  chiefly  un- 
crossed. 

The  axones  of  the  red  nucleus  neurones,  which  form  the 
rubro-spinal  tract,  emerge  from  the  ventro-medial  surface 
of  the  nucleus,  cross  the  middle  line  at  the  decussation  of 
Forel,  and  bend  downward  within  the  tegmentum  of  the 
mid-brain  and  pons  to  reach  the  medulla,  finally  entering 
the  lateral  columns  of  the  cord  as  an  important  but  uncer- 
tainly defined  descending  tract,  which  may  be  fairly  rep- 
resented as  the  intermediate  fasciculus.  The  cerebello- 
rubro-thalamico-cortical  paths  are  mainly  crossed,  while 
the  cerebello-rubro-spinal  tracts,  owing  to  a  double  decus- 
sation, bring  the  cerebellum  into  relation  mainly  with  the 
motor  root  cells  of  the  same  side. 

2.  Fibres  to  the  oculo-motor  nucleus  of  the  opposite 
side.  These  fibres  contain  the  afferent  pupil  reflex  path 
(v.   Bechterew  ^^) ,  but  they  also  contain  efferent  paths, 


48  SEMICIRCULAR   CANALS 

probably  concerned  in  the  conjugate  movements  of  the 
eves.     This  tract  is  crossed. 

The  dorsal  zones  of  the  early  metencephalon  besides 
providing  the  reception  nuclei  of  the  sensory  cranial 
nerves,  and  perhaps  of  the  pontine  nuclei,  contribute  the 
neuroblasts,  which  become  the  nervous  elements  of  the 
cerebellmn.  The  ventral  zones  play  an  active  part  in 
producing  the  tegmental  portion  of  the  pons  and  nuclei 
of  origin  of  the  fifth,  sixth,  and  seventh  cranial  nerves. 
As  in  the  medulla  so  in  the  pons,  the  ventral  tracts  are 
relatively  late  additions  to  the  tegmentum,  which  is  the 
primary  and  oldest  part  of  this  segment  of  the  brain  stem. 
The  bulky  ventral  nervous  masses  take  fonn  only  after 
the  appearance  of  the  cerebro-spinal  and  cerebro-cerebellar 
paths.  The  hmnan  cerebellum  is,  therefore,  developed 
from  the  roof-x:)late  and  adjacent  parts  of  the  dorsal  zones 
of  the  lateral  walls  of  the  metencephalon. 

The  posterior  longitudinal  fasciculus  contains : 

1.  Fibres  from  the  nucleus  of  the  posterior  commissure 
(Darkschewitsch's  nucleus)  in  advance  of  the  third  nerve 
nucleus  in  the  grey  matter,  about  the  upper  end  of  the 
Sylvian  aqueduct.  The  fibres  cross  to  join  the  fasciculus 
of  the  opposite  side. 

2.  Fibres,  also  crossed,  from  the  nucleus  fasciculi 
longitudinalis  dorsalis  in  the  grey  matter  of  the  floor  of 
the  third  ventricle  in  the  vicinity  of  the  corpus  mam- 
millare. 

3.  Fibres  crossed  and  uncrossed  from  the  vestibular 
(Deiters')  nucleus.  For  reasons  already  stated  in  dis- 
cussing the  vestibular  connections,  it  is  highly  improbable 
that  the  paths  lying  between  Deiters'  nucleus  and  the 
posterior  longitudinal  fasciculus  merely  represent  the  con- 
tinuations of  paths  from  the  semicircular  canals  to  Deiters' 
nucleus,  and  thence  to  the  ocular  and  other  nuclei.  Many 
of  the  fibres  undoubtedly  are  continuations  of  paths  from 
the  cerebellum  and  other  higher  centres,  perhaps,  and 
carry  efferent  impulses,  whilst  others  are  afferent — the 
continuations  perhaps  of  vestibular  paths,  but  their  main 
o])jective  ])oint  is  not  the  sixth  nucleus,  but  rather  some 
higher  coordinating  centre.  Either  of  these  suppositions 
makes  it  possible  to  explain  the  phenomena  observed  on 
stimulating  the  area  corresponding  to  the  location  of  the 


ANATOMY  49 

Bixth  nerve  nucleus  without  according  this  latter  centre 
the  dignity  of  a  coordinating  centre  for  the  other  ocular 
muscles,  and  also  without  encountering  the  awkward  ob- 
jections the  latter  hypothesis  entails. 

4.  Fibres  from  the  abducens  nucleus  to  the  oculo- 
motor nucleus.  The  existence  of  these  or  of  any  fibres 
leaving  the  abducens  nucleus  to  enter  the  posterior  longi- 
tudinal fasciculus  is  denied  by  Schafer.^^ 

5.  Fibres  from  the  reception  nuclei  of  the  remaining 
sensory  nerves  of  the  brain  stem  of  the  same  and  opposite 
sides.  These  fibres  are  probably  all  afferent,  their  objec- 
tive point  being  the  higher  coordinating  centres,  and 
perhaps  also  centres  at  other  levels,  which  by  their  means 
— through  the  posterior  longitudinal  fasciculus — may  be 
brought  into  relation  for  reflex  movements  of  a  lower 
order. 

6.  Fibres  traversing  the  commissura  hypothalamica 
(Edinger  ^) ,  to  reach  probably  the  mammillary  body  of 
the  opposite  side. 

7.  Fibres  probably  also  to  the  thalamus,  subthalamic 
region,  the  corpora  quadrigemina,  the  red  nucleus,  and 
the  cerebellum. 

The  connections  of  the  posterior  longitudinal  fascicu- 
lus are  important  and  far-reaching,  but  they  have  been 
only  imperfectly  worked  out.  The  connection  with  the 
cerebellum  is  undoubted,  and  yet  no  definite  path  of  any 
importance  has  been  traced.  The  same  has  to  be  said  of 
its  connections  with  other  higher  centres. 

Connections  of  the  Mesial  Fillet  or  Lemniscus 

1.  Fibres  from  the  nucleus  gracilis  and  nucleus  cunea- 
tus  which,  for  the  most  part,  cross  the  middle  line  as  the 
arcuate  filDres  making  the  sensory  decussation  about  the 
upper  border  of  the  pyramidal  decussation  in  the  lower 
part  of  the  medulla  oblongata.  This  sensory  decussation 
marks  the  lowest  limit  of  the  fillet  and  the  fibres  compos- 
ing it  are  continuations  of  the  paths  represented  in  the 
posterior  fasciculi  of  the  cord,  viz.,  those  of  Goll  and 
Burdach  derived  from  the  posterior  nerve  roots  of  the 
same  side.     The  fillet  tract  is  mainly  crossed. 

2.  Fibres  from  the  reception  nuclei  of  all  the  sensory 


50  SEMICIRCULAR   CANALS 

cranial  nerves  connected  with  the  brain  stem.  These 
fibres  are  mainly  crossed. 

8.  Fibres  from  the  cells  of  the  more  extensive  nuclei, 
e.g.,  from  those  of  the  substantia  gelatinosa.  Accom- 
panying the  spinal  root  of  the  fifth  nerve,  numerous  fibres 
sweep  toward  the  raphe  and,  with  few  exceptions,  cross 
to  join  the  fillet  of  the  opposite  side. 

These  three  sets  of  fibres  constituting  the  bulbo-tecto- 
thalamic  tract  course  upward  through  the  tegmentum. 
Many  of  the  fibres  end  around  the  deeper  grey  stratum  of 
the  superior  coUiculus,  some  passing  over  the  aqueduct  of 
Sylvius  to  the  opposite  colliculus.  The  remaining  fibres 
pass  on  to  reach  the  cells  in  the  ventral  part  of  the  optic 
thalamus,  thence  the  paths  are  continued  to  various  parts 
of  the  cerebral  cortex.  Other  fibres  said  to  be  derived 
from  the  cuneate  nucleus  end  in  the  corpus  subthalami- 
cum  and  the  lenticular  nucleus.  From  the  cells  of  the 
latter,  fibres  proceed  through  the  commissure  of  Meynert 
— a  strand  j^laced  just  above  the  optic  chiasm — to  the 
lenticular  nucleus  of  the  opposite  side.  Still  other  fibres 
can  he  traced  into  the  posterior  commissure  of  the  brain 
and  into  the  mammillary  body. 

The  fillet  has  also  strands  running  in  an  opposite 
direction.     Some  of  these  are  probably: 

4.  Fibres  from  the  cells  of  the  optic  thalamus  and 
corpora  quadrigemina. 

5.  Efferent  strands  which  establish  connections  between 
the  cerebral  cortex  and  the  nuclei  of  the  motor  cranial 
nerves,  especially  the  seventh  and  twelfth.  These  cortico- 
bulbar  tracts  join  the  median  fillet  in  the  upper  part  of 
the  pons,  and  descend  with  it  as  far  as  the  upper  limit  of 
the  twelfth  nucleus.  This  part  is  often  called  the  crustal 
fillet.  On  reaching  the  levels  of  the  various  nuclei,  the 
fibres  destined  for  them  undergo  decussation  for  the  most 
part. 

6.  Fibres  from  the  cerebellum  via  the  spinal  bundle 
of  the  middle  peduncle  to  the  corpora  quadrigemina  (v. 
Bechterew). 


ANATOMY  51 

Connections  of  the  Superior  CoUiciiU  of  the  Corpora 

Quadrige7nina 

Afferent  paths,  i  e.,  to  the  coUiciili. 

1.  Fibres  from  the  optic  tract  through  the  superior 
brachium  directly,  or  after  interruption  in  the  lateral  gen- 
iculate body.  Probably  some  fibres  cross  to  the  opposite 
colliculus  through  the  commissure  of  the  superior  col- 
liculi. 

2.  Possibly  fibres  from  the  lateral  geniculate  body  as 
continuations  of  the  paths  from  the  occipital  cortex  to 
the  lateral  geniculate  body.  These  latter  run  in  the  optic 
radiation,  but  are  centrifugal. 

3.  With  the  posterior  sensory  tracts  of  the  cord 
through  the  median  fillet.  Probably  some  fibres  cross  to 
the  opposite  colliculus  by  way  of  the  commissure. 

4.  With  the  cochlear  nuclei  by  way  of  the  lateral  fillet. 

5.  Fibres  between  the  superior  colliculi  and  the  pos- 
terior longitudinal  fasciculus  connecting  the  nuclei  of  the 
third,  fourth,  and  sixth  cranial  nerves  with  the  superior 
colliculus.  These  are  part  of  the  undemonstrated  fibres 
mentioned  in  the  connections  of  the  posterior  longitudi- 
nal fasciculus. 

6.  Probably  spino-tectal  fibres  travelling  with  the 
tecto-spinal  tract,  but  in  the  reverse  direction. 

7.  Fibres  from  the  substantia  nigra  by  way  of  the 
fillet  (v.  Bechterew  ^^) . 

8.  Fibres  from  the  cerebellum  by  way  of  the  spinal 
bundle  of  the  middle  peduncle  through  the  median  fillet 
(v,  Bechterew  ^^) . 

Note. — The  fibre  paths  grouped  under  5  and  8  are  probably 
the  afferent  cerebellar  paths  which  control  the  reflex  conjugate 
movements  of  the  eyes  and  the  various  forms  of  physiological 
nystagmus. 

Efferent  paths,  i.e.,  from  the  superior  colliculi. 

1.  The  tecto-bulbar  and  tecto-spinal  tracts.  These 
fibres  emerge  from  the  ventral  borders  of  the  colliculi. 
The  more  medially  situated  fibres  cross  the  raphe  to  form, 
with  the  corresponding  fibres  of  the  opposite  side,  the 
fountain  decussation  of  Meynert,  just  ventral  to  the  pos- 


52  SEMICIRCULAR  CANALS 

fcerior  longitudinal  fasciculus.  The  destinations  of  the 
fibres  of  these  tracts  are  (1)  the  nuclei  within  the  brain 
stem;  (2)  undetermined  nuclei  in  the  spinal  cord,  most 
probably  the  ventral  root  cells.  The  fibres  to  the  spinal 
cord  pass  by  way  oft  the  anterior  column  of  the  cord  (fas- 
ciculus sulco-marginalis) ,  whether  directly  or  after  inter- 
ruption being  undetermined.  The  tracts  are  partly 
crossed. 

2.  Some  of  the  fibres  as  they  emerge  from  the  colliculi 
can  be  traced  through  the  tegmentum,  passing  to  the 
outer  side  of  the  red  nucleus,  piercing  the  median  fillet 
and  entering  the  substantia  nigra. 

3.  Fibres  in  the  commissure  of  the  superior  colliculi 
as  axones  of  the  cells  of  the  colliculi. 

4.  Possibly  fibres  to  the  lateral  geniculate  body,  the 
path  being  continued  thence  to  the  occipital  cortex. 

Connections  of  the  Lateral  Genimilate  Body 

Afferent  paths,  i.e.,  to  the  geniculate  body. 

1.  Fibres  of  the  outer  division  of  the  optic  tract. 

2.  Fibres  (cortifugal)  from  the  occipital  cortex  by 
way  of  the  optic  radiation. 

Efferent  paths,  i.e.,  from  the  geniculate  body. 

1.  Fibres  to  the  superior  colliculus  through  the  supe- 
rior brachium.  Some  fibres  probably  reach  the  opposite 
colliculus  through  the  commissure  of  the  superior  col- 
liculi. The  superior  brachium  contains  also  fibres  from 
the  optic  tract  that  reach  the  superior  colliculus  without 
interruption  in  the  lateral  geniculate  body. 

2.  Fibres  to  the  occipital  cortex  by  way  of  the  optic 
radiations. 

Connections  of  the  Lateral  Fillet  or  Lemniscus 
Lateralis 

Afferent  paths,  i.e.,  toward  the  cerebrum. 

L  Fibres  from  the  superior  olivary  nucleus  of  the 
same  side,  which  represent  the  continuation  of  the  coch- 
lear paths,  chiefly  from  the  opposit(3  auditory  nuclei  to 


ANATOMY  58 

the  inferior  colliciilus  and  median  geniculate  body,  and 
through  these  latter  by  way  of  the  auditory  radiation  to 
the  cortex.  Some  fibres  from  the  superior  olivary  nucleus 
pass  to  the  sixth  nucleus,  and  by  way  of  the  posterior 
longitudinal  fasciculus  to  the  nuclei  of  the  third  and 
fourth  cranial  nerves.  But  see  observations  on  the  simi- 
lar connections  of  the  vestibular  nucleus. 

2.  Fibres  from  the  cells  of  the  nucleus  of  the  lateral 
fillet,  and  possibly  fibres  from  the  nucleus  tegmenti 
lateralis  of  Kolliker. 

3.  Fibres  from  the  acoustic  striae  after  mesial  decus- 
sation. 

The  fibres  of  the  lateral  fillet  end  partly  in  the  cells  of 
the  inferior  coUiculus,  and  in  those  of  the  median  genicu- 
late body,  the  paths  being  continued  by  axones  from  the 
cells  of  these  bodies  to  the  auditory  cortical  areas.  Some 
fibres  of  the  lateral  fillet  probably  reach  the  inferior  col- 
liculus  of  the  opposite  side  through  the  commissure  of  the 
inferior  colliculi. 

The  lateral  fillet  mainly  represents  a  crossed  afferent 
cochlear  path. 

Connections  of  the  Inferior  Colliculi 

Afferent  paths,  i.e.,  to  the  colliculi. 

1.  Fibres  from  the  lateral  fillet  ending  about  the  cells 
of  the  nucleus  of  the  inferior  colliculus  of  the  same  side, 
some  fibres  probably  reaching  the  opposite  colliculus  by 
way  of  the  commissure  of  the  inferior  colliculi. 

2.  Fibres  from  the  cerebral  cortex,  especially  from  the 
temporal  lobe  through  the  inferior  brachium. 

Efferent  paths,  i.e.,  from  the  colliculi. 

1,  Fibres — axones  of  the  cells  of  the  inferior  colliculi  — 
which  continue  the  paths  of  the  lateral  fillets  interrupted 
in  the  colliculi.  These  fibres  joining  with  those  con- 
tinued from  the  lateral  fillet  are  the  chief  constituents  of 
the  inferior  brachia. 

2.  Fibres  to  the  tecto-bulbar  and  tecto-spinal  tracts. 
8.  Fibres  also  pass  by  way  of  the  superior  medullary 

velum  to  the  medulla  of  the  worm. 


54  SEMICIRCULAR  CANALS 

Coimections  of  tlie  Median  Geniculate  Bodies 

Afferent  paths,  i.e.,  to  the  geniculate  bodies  through  the 
inferior  brachium. 

1.  Fibres  from  the  lateral  fillets  which  end  about  the 
cells  of  the  nuclei  of  the  median  geniculate  bodies.  These 
are  the  fibres  that  have  not  been  interrupted  in  the  in- 
ferior colliculi. 

2.  Probably  fibres  from  the  auditory  cortex. 

Efferent  paths,  i.e.,  from  the  geniculate  bodies. 

1.  Fibres  forming  the  lateral  root  of  the  optic  tract 
known  as  the  inferior  commissure  of  Gudden.  After 
decussation  many  of  these  fibres  probably  are  directed 
toward  the  lenticular  nucleus.  Some  fibres  may  possibly 
end  in  the  subthalamic  nucleus  of  the  same  side. 

The  existence  of  fibres  from  the  median  geniculate 
body  to  the  median  root  of  the  optic  nerve  has  been 
demonstrated.  These  fibres  are  not  concerned  in  vision, 
and  do  not  atrophy  after  enucleation  of  the  eye  as  do 
retinal  fibres.  They  probably  represent  in  us  older  and 
little  used  paths  for  protective  reflexes  analogous  to  those 
paths  which  enable  the  frog,  deprived  of  its  cerebrum, 
to  "see"  sufficiently  to  escape  objects  in  jumping, 
although  it  is  unable  to  recognize  anything.  Similar 
unused  paths  can  be  traced  in  the  olfactory  organs.  It  is 
possible  that  these  paths  may  still  function  to  some 
extent  in  abnormal  conditions  of  heightened  irritability, 
as  in  the  nausea  of  seasickness. 

2.  Fibres — the  axones  of  the  cells  of  the  median  gen- 
iculate bodies — which  continue  the  paths  of  the  lateral 
fillet,  not  interrupted  in  the  inferior  colliculi,  to  the  audi- 
tory cortex. 

Connections  of  the  Inferior  Olivary  Nucleus 

Afferent  paths,  i.e.,  toward  the  nucleus. 

1.  Fibres  from  the  cerebellar  cortex,  the  worm,  and 
the  nucleus  dentatus  through  the  restiform  body,  through 
the  nucleus  of  the  same  side,  mainly  without  interruption, 
across  the  middle  line,  to  end  in  the  nucleus  of  the  oppo- 


ANATOMY  55 

site  side.  These  fibres  constitute  an  efferent  cerebellar 
path,  continued,  perhaps,  by  fibres  which  spring  as 
axones  of  the  olivary  cells,  and  which  descend  in  the 
anterior  ground  bundle  of  the  cord  (Kolliker).  It  is 
probable  that  the  paths  represented  here  cross  the  middle 
line  twice.      (See  "Efferent  paths"  below.) 

2.  Fibres  from  Deiters'  nucleus,  which  pass  to  the 
olive  of  the  same  side,  thence  across  the  middle  line  to 
the  olive  on  the  opposite  side,  and  through  the  restiform 
body  to  the  cerebellum.  These  fibres  represent,  in  part  at 
least,  the  continuation  of  vestibular  paths  interrupted  in 
Deiters'  nucleus,  and  are  generally  known  as  the  descend- 
ing vestibular  olivary  tract.  It  seems  more  correct  to  call 
them  the  crossed  vestibulo-olivo-cerebellar  tract  for  reasons 
stated  in  discussing  the  vestibular  connections. 

3.  Fibres  from  Helweg's  fasciculus,  probably  an  affer- 
ent cerebellar  pathway. 

Efferent  paths,  that  is,  from  the  inferior  olivary  nucleus. 

1.  Fibres  as  axones  of  the  olivary  cells  passing  down 
in  the  anterior  ground  bundle  of  the  cord  (Kolliker). 
These  fibres  in  part  may  represent  the  continuations  of 
efferent  cerebellar  paths,  beginning  in  the  roof  nucleus, 
thence  to  Deiters'  nucleus  of  the  opposite  side,  thence 
w^ith  or  without  interruption  they  descend  to  the  inferior 
olive  on  the  same  side,  and  crossing  to  the  opposite  olive 
end  about  the  neurones  of  the  olivary  nucleus.  Such  a 
pathway  crosses  the  middle  line  twice,  bringing  thus  each 
half  of  the  cerebellmn  into  relations  with  the  structures 
on  the  same  side  of  the  body.  See  "Olivo-cerebellar 
fibres,"  under  the  connections  of  the  inferior  peduncle. 
Another  possible  means  of  double  decussation  of  these 
paths  is  discussed  under  the  vestibulo-sj)inal  tract  in  the 
cord  (q.v.). 

2.  Fibres  from  the  inferior  olive  to  the  opposite  olive, 
thence  through  the  restiform  body  to  the  cerebellar  cortex, 
the  worm  and  the  nucleus  dentatus.  Some  fibres  ascend 
to  the  cerebellmn  from  the  olive  of  the  same  side.  This 
set  of  efferent  olivary  fibres  consists  mainly  of  afferent 
cerebellar  fibres,  and  represents  most  probably  the  con- 
tinuation of  vestibular  paths,  interrupted  in  Deiters' 
nucleus,  and  perhaps  also  in  either  one  of  the  olivary 


56  SEMICIRCULAR   CANALS 

nuclei.  This  set  of  fibres  is  mentioned  under  both  afferent 
and  efferent  paths,  because,  owing  to  the  peculiar  relations 
of  the  olives  to  each  other,  the  fibres  that  are  afferent  to 
one  olive  are  frequently  efferent  in  relation  to  the  other. 

The  accessor}^  olivaiy  nuclei  are  two  irregular,  plate- 
like masses  of  grey  matter  that  lie  respectively  mesially 
and  dorsally  to  the  chief  olive.  Their  connections  are  in 
the  main  those  of  the  chief  olivary  nuclei. 

Connections  of  the  Superior   Olivary  Nucleus 
Afferent  paths,  i.e.,  to  the  nucleus. 

\.  Fibres  from  the  cochlear  nuclei,  mainly  of  the 
opposite  side.  The  continuation  of  these  paths,  after 
interruption  in  the  superior  olive,  represents  the  chief 
source  of  the  lateral  fillet.  The  axones  of  the  ventral 
cochlear  nucleus  and,  to  some  extent,  those  of  the  lateral 
cochlear  nucleus,  as  they  traverse  the  upper  part  of  the 
pons  toward  the  superior  olive  on  the  opposite  side  form 
a  conspicuous  transverse  tract — the  corpus  trapezoides — 
that  separates  the  tegmental  from  the  ventral  region  of  the 
pons.  Some  large  cells  found  within  the  corpus  trape- 
zoides are  known  as  the  nucleus  trapezoideus.  These 
cells  give  off  axones  to  the  trapezoid  body  paths,  and 
probably  in  part  to  the  superior  olivary  nucleus. 

2.  Fibres  from  the  lateral  half  of  the  cerebellum  of  the 
same  side  as  the  cerebello-superior  olivary  tract.  Accord- 
ing to  V.  Bechterew  these  fibres,  after  decussating  in  the 
middle  line,  pass  from  the  cerebellar  roof  nucleus,  and  go 
directly  or  through  the  fibres  of  the  trapezius  to  the 
superior  olive.  There  is  reason  for  believing  that  this  is 
a  cerebellar  centripetal  tract,  Vjut  v.  Bechterew  l^elieves  it 
to  be  centrifugal  because  of  the  direct  communication  of 
the  superior  olive  with  the  abducent  nuclei,  and  because 
of  the  relation  of  the  latter  to  reflex  ocular  movements. 

Efferent  paths,  i.e.,  from  the  nucleus. 

1.  Fibres,  as  axones  of  the  nucleus,  which  are  the  chief 
source  of  origin  of  the  lateral  fillet.  Th(?y  represent  the 
continuation  of  cochlear  paths  t/)  the  inferior  colliculus, 
median  geniculate)  body,  and  auditory  cort(3x. 

2.  Fibres  to  the  nucleus  of  the  sixth  nerve  and  other 


ANATOMY  57 

fibres  by  way  of  the  posterior  longitudinal  fasciculus  to 
the  other  oculo-motor  nuclei.  For  reasons  stated  in  dis- 
cussing the  vestibular  connections  with  the  sixth  nucleus, 
these  fibres  are  not  to  be  considered  as  altogether  mere 
continuations  of  cochlear  paths,  but  are  rather  to  be  taken 
in  the  main  as  a  part  of  many  efferent  paths  from  higher 
coordinating  centres,  e.g.,  the  cerebellum. 

V.  Bechterew  ^^  considers  these  fibres  as  the  continua- 
tion of  a  cerebello-superior  olivary  tract,  carrying  cere- 
bellar centrifugal  impulses,  and  analogous  to  the  fibres 
in  the  superior  cerebellar  peduncle  to  the  oculo-motor 
nucleus  of  the  opposite  side.  This  opinion  is  in  harmony 
with  the  views  repeatedly  expressed  in  these  pages  con- 
cerning the  relations  between  the  various  cranial  nerve 
nuclei,  and  notably  between  the  vestibular,  sixth  and 
third  nerve  nuclei. 

The  cerebellum  consists  of  two  lateral  lobes  or  hemi- 
spheres connected  by  a  median  lobe,  the  vermis.  All 
these  divisions  are  subdivided  into  various  lobules,  the 
surfaces  of  which  are  marked  by  parallel  transverse  folds 
or  laminse,  which  give  off  secondary  and  tertiary  laminae. 
The  general  appearance  presented  on  section  is  known  as 
the  arbor  vitae.  The  surface  of  the  cerebellum  is  com- 
posed of  grey  matter,  the  cortex,  enveloping  the  white 
matter.  There  are  also  masses  of  grey  matter — the  in- 
ternal nuclei — within  the  cerebellum  imbedded  in  the 
white  matter.     The  fibres  that  enter  the  cerebellum  are : 

1.  From  the  restiform  body,  (a)  from  the  dorsal 
spino-cerebellar  tract  to  the  cortex  of  the  vermis;  (b) 
olivo-cerebellar  fibres  to  the  whole  cortex;  (c)  fibres  from 
the  lateral  nucleus,  and  possibly  from  other  nuclei  in  the 
reticular  formation. 

2.  The  continuations  of  vestibular  root-fibres  to  the 
vermis. 

3.  Fibres  from  the  ventral  spino-cerebellar  tract  to  the 
vermis. 

4.  Fibres  from  the  nucleus  pontis  to  the  cortex  of  the 
hemispheres. 

The  internal  cerebellar  nuclei  are:  (1)  the  dentate 
nucleus;  (2)  the  roof  nucleus  or  nucleus  fastigii;  (8)  the 
nucleus  emboliformis;  and  (4)  the  nucleus  globosus. 
The   globosus   is   connected    by   uncertain   and   limited 


58  SEMICIRCULAR  CANALS 

attachments  with  the  roof  nucleus  and  embolus.  It  is 
also  connected  with  the  postero- inferior  part  of  the  den- 
tate nucleus.  Hence  these  nuclei  are  more  or  less  con- 
tinuous masses  of  grey  matter.  The  globosus  and  emboli- 
fomiis  are  but  incompletely  separated  parts  of  the  nucleus 
dentatus.  The  cortical  cells  do  not  send  axones  outside 
the  cerebellum,  all  efferent  paths  being  interrupted  in  the 
internal  nuclei.  The  dentate  nucleus  receives  fibres  from 
the  cortex  of  the  hemispheres.  The  globosus  and  emboli- 
formis  receive  fibres  from  the  cortex  of  the  vermis,  whilst 
the  nucleus  fastigii  receives  fibres  from  various  parts. 
The  axones  of  the  nucleus  fastigii  (fastigio-bulbar fibres), 
for  the  most  part  as  crossed  paths,  pass  to  the  vestibular 
and,  possibly,  to  other  reticular  formation  nuclei.  The 
axones  of  the  remaining  internal  cerebellar  nuclei  pass  in 
the  superior  peduncle.  There  may  be  some  efferent  fibres 
in  the  middle  peduncle  to  the  reticular  formation  nuclei, 
but  the  greater  part  of  this  peduncle  consists  of  ponto- 
cerebellar fibres.  The  inferior  and  middle  peduncles  are 
thus  largely  afferent,  whilst  the  superior  peduncle  is  effer- 
ent in  great  part  to  the  red  nucleus,  thalamus,  and  nucleus 
of  the  third  nerve. 

The  commissural  tracts  constitute  part  of  the  white 
matter  of  the  cerebellum. 

The  anterior  (superior)  commissure  is  the  larger,  and 
lies  in  front  of  the  dentate  nucleus,  whilst  the  posterior 
(inferior)  commissure  lies  behind  the  nucleus.  Each 
crosses  the  middle  line  to  pass  into  the  opposite  hemi- 
sphere, thus  constituting  the  anterior  and  posterior  cere- 
bellar decussations. 

Connections  of  the   Worm  ( Verynis) 

Within  the  substance  of  the  worm  are: 

\.  The  superior  cerebellar  commissure.  This  consists 
of  fibres  passing  in  front  of  the  roof  nucleus.  Beyond 
the  worm  on  either  side  the  fibres  expand  into  the  main 
limbs  of  the  medullary  tree.  This  commissure  is  the  main 
link  between  the  cortical  areas  of  the  cerebellar  hemisphere. 

2.  The  inferior  cerebellar  commissure  passes  behind 
the  roof  nucleus  as  a  number  of  email  transversely  cours- 
ing bundles. 


ANATOMY  59 

8.  The  decussation  of  the  roof  nuclei.  This  differs 
from  the  commissural  tract  just  mentioned.  It  consists 
of  rounded  bundles  traversing  the  roof  nucleus,  especi- 
ally its  anterior  (superior)  part.  More  distally  the  fibres 
skirt  the  dorsal  margin,  and  still  farther  backward  they 
invade  the  beginning  of  the  medullary  limb. 

4.  The  median  sagittal  bundle  extends  from  the  supe- 
rior medullary  velum,  beneath  the  roof  nucleus  into  the 
medulla  of  the  worm.  Above,  these  fibres  are  continued 
upward  through  the  medullary  velum  and  into  the  inferior 
colliculus. 

The  separate  extra-cerebellar  connections  of  the  worm   * 
have  not  been  successfully  traced.     Various  experiments, 
however,  point  to  the  worm  as  containing  most  important 
coordinating  centres  with  wide  peripheral  relations. 

The  superior  medullary  velum  is  a  sheet  of  white  mat- 
ter extending  from  beneath  the  corpora  quadrigemina  to 
the  medullary  substance  of  the  cerebellum.  Laterally,  it 
is  attached  to  the  superior  cerebellar  peduncles,  thus 
forming  the  roof  of  the  upper  part  of  the  fourth  ventricle, 
where  its  ventral  surface  is  lined  by  ependpna.  Dor- 
sally,  it  is  overlaid  by  the  rudimentary  folia  of  the 
lingula.     Its  connections  are: 

1.  Fibres  of  the  median  sagittal  bundle  passing  be- 
tween the  medulla  of  the  worm  and  the  inferior  coUiculi. 
The  function  of  these  fibres  has  not  been  detennined. 

The  inferior  medullary  velum  also  consists  of  white 
matter,  and  is  attached  for  some  distance  to  the  front  and 
lower  surface  of  the  nodule.  Its  connections,  so  far  as 
known,  are  merely  mechanical. 

The   fourth  ventricle   communicates   freely  with   the 
subarachnoid  space  of  the  cord  through  the  foramen  of 
Magendie,  situated  in  the  median  part  of  the  roof  of  the  * 
fourth    ventricle,    and    also    through    the    foramina    of 
Luschka  in  the  lateral  recesses  of  the  ventricle. 

Connectiofis  of  the  Pontine  Nucleus 

Afferent  paths,  i.e.,  to  the  nucleus. 

1.  Fibres  from  the  cortex  of  the  frontal,  temporal,  and 
occipital  lobes  of  the  same  side  as  constituents  of  the 
fronto-cerebellar  and  temporo-occipito-cerebeUar  tracts. 


60  SEMICIRCULAR   CANALS 

2.  Collaterals  from  the  pyramidal  tracts,  thus  estab- 
lishing connections  between  the  motor  areas  of  the  cortex 
and  the  pontine  nuclei. 

Efferent  paths,  i.e.,  from  the  nucleus. 

1.  Ponto-cerebellar  fibres — the  immediate  constituents 
of  the  middle  peduncle — which,  for  the  most  part,  cross 
the  middle  line  to  reach  all  parts  of  the  cortex  of  the 
cerebellar  hemisphere  and  of  the  worm,  and  possibly 
the  nucleus  dentatus. 

According  to  some  authors  the  assumption  that  the 
*  efferent  cerebello-pontine  fibres  end  about  the  cells  of  the 
pontine  nucleus  lacks  the  support  of  more  recent  observa- 
tions. (See  note  on  the  Connections  of  the  middle  cere- 
bellar peduncle.) 

The  red  nucleus  consists  of  an  ovoid  reticulated  field 
on  either  side  of  the  median  line  in  the  upper  half  of  the 
mid-brain,  extending  from  the  lower  border  of  the  su- 
perior colliculus  to  a  short  distance  within  the  subthala- 
mic region.  Each  nucleus  consists  of  a  complex  of  gxey 
matter  and  fibres. 

Connectio7is  of  the  Bed  Nucleus  (Nucleus  Ruber, 
Nucleus  Tegmenti) 

Afferent  paths,  i.e.,  to  the  nucleus. 

1.  Fibres  from  the  superior  cerebellar  peduncle.  As 
the  decussation  of  this  peduncle  begins  about  the  upper 
third  of  the  inferior  colliculus,  and  is  best  marked  oppo- 
site the  superior  colliculi,  it  is  evident  that  the  red 
nucleus  receives  fibres  as  follows:  (a)  uncrossed  fibres 
from  the  peduncle  of  the  same  side;  (b)  crossed  fibres 
from  the  peduncle  (;f  the  opposite  side. 

2.  Fibres  of  the  efferent  cerebello-pontine  tract  in  the 
middle  peduncle  (v.  Bechterew).  These  fibres  represent 
a  crossed  path  from  the  half  of  the  cerebellum  on  the 
oppositf3  side. 

8.  Fibres  that  enter  the  nucleus  on  its  lateral  aspect 
from  the  cerebral  cortex  (Dejerine^^)  and  probably  also 
from  the  corpus  striatum  (Edinger),  e.g.,  fibres  included 
in  the    tractus    strio-thalamicus,   which   pass    from   the 


ANATOMY  61 

caudate  nucleus  and  putamen  to  the  thalamus,  subthala- 
mic body,  and  the  red  nucleus. 

Efferent  paths,  i.e.,  from  the  nucleus. 

1.  Fibres  to  the  optic  thalamus  as  axones  of  the 
rubral  neurones.  These  fibres  represent  the  continuation 
of  the  paths  of  the  superior  cerebellar  j^eduncle,  inter- 
rupted in  the  nucleus.  From  the  thalamus  the  path  is 
continued  to  the  cerebral  cortex. 

2.  Fibres — the  axones  of  the  rubral  neurones — which 
join  the  rubro-spinal  tract,  having  crossed  in  the  decussa- 
tion of  Forel.  These  represent  the  continuation  of  the 
paths  from  the  cerebral  cortex  and  corpus  striatum,  and 
are  to  be  considered  as  indirect  motor  paths  supplemental 
to  the  cortico-spinal  pyramidal  tracts. 

8.  Fibres — the  axones  of  the  rubral  neurones — which 
emerge  from  the  ventro-medial  surface  of  the  nucleus, 
cross  the  middle  line  in  the  decussation  of  Forel,  and 
turn  downward  as  the  rubro-spinal  tract.  This  latter 
descends  within  the  tegmentum  of  the  mid-brain  and 
pons,  traverses  the  medulla,  and  finally  enters  the  lateral 
column  of  the  cord. 

The  rubro-spinal  tract,  therefore,  carries  efferent  im- 
pulses as  follows : 

1.  From  the  cerebral  cortex  and  corpus  striatum  of  the 
opposite  side,  the  path  crossing  once  in  the  decussation 
of  Forel. 

2.  From  the  cerebellum  of  the  same  side,  (a)  by  way 
of  the  superior  peduncle,  the  path  crossing  in  the  pedun- 
cular decussation  and  recrossing  in  Forel's  decussation; 
(b)  by  way  of  the  middle  peduncle,  the  path  crossing  in 
the  pons  to  reach  the  red  nucleus  and  recrossing  in 
Forel's  decussation.  Ferrierheld  that  the  middle  pedun- 
cular fibres,  after  crossing  the  middle  line,  join  the  py- 
ramidal tracts  and  recross  in  the  decussation  of  the  latter. 

The  optic  thalamus  is  mainly  a  great  ganglionic  inter- 
node  in  the  corticipetal  paths.  Most  of  the  afferent  paths 
from  the  cord,  brain-stem,  and  cerebellum  end  about  its 
cells,  thence  corticipetal  fibres  pass  to  all  parts  of  the 
cerebral  cortex  and  to  the  corpus  striatum.  The  thala- 
mus also  receives  fil^res  from  all  parts  of  the  cerebral  cor- 
tex, and  from  it  efferent  fibres  proceed  to  the  lov^ex  cer^tre^ 


62  SEMICIRCULAR   CANALS 

in  the  brain-stem  and  cord.  The  stratum  zonale  is  a  thin 
layer  of  nerve  fibres  on  the  superior  surface  of  the  thala- 
mus. The  fibres  can  be  traced  to  the  optic  tract  on  the 
one  hand  and  to  the  optic  radiations  on  the  other.  The 
thalamus  is  connected  with  its  fellow  by  a  bridge  of  grey 
matter  with  few  white  fibres,  the  massa  intermedia.  Lat- 
erally the  thalamus  blends  with  the  internal  capsule.  The 
reticulated  stratum  on  the  ventro-lateral  surface  consti- 
tutes the  medullary  lamina.  It  consists  of  numerous 
fibres  to  and  from  the  thalamus.  The  ventral  surface  of 
the  thalamus  rests  on  the  prolongation  of  the  tegmental 
part  of  the  cerebral  peduncle,  and  is  called  the  subthalamic 
tegmental  region.  The  ventral  nucleus  receives  the  great 
sensory  paths.  This  nucleus  and  the  ganglion  habenulse 
are  the  oldest  of  the  thalamic  nuclei,  being  found  in  all 
vertebrates  (Edinger^^). 

The  optic  thalamus,  subthalamic  body,  and  the  lateral 
geniculate  body  constitute  the  main  divisions,  in  regard 
to  function,  of  the  diencephalon.  The  thalamus  itself 
contains  some  twenty  grey  nuclei  (Nissl,  v.  Monakow). 
The  subthalamic  body  and  the  lateral  geniculate  body 
may  be  regarded  as  grey  nuclei,  somewhat  analogous  to 
the  nuclei  of  the  thalamus,  only  more  distinctly  separable 
from  the  latter  structure.  Relatively  to  its  bulk  the 
region  sends  few  fibres  caudally,  but  it  sends  numerous 
fibres  to  the  telencephalon  (c.  striatum  and  cortex) . 

Connections  of  the  Optic  Thalamus 

Afferent  paths,  i.e.,  to  the  thalamus. 

1.  Fibres  directly  from  the  cord  as  the  spino-thalamic 
and  probably  some  from  Gowers'  tract.  The  relation  is 
mainly  a  crossed  one. 

2.  Fibres  from  the  cerebellum,  (a)  directly,  as  cere- 
bello-thalamic  fibres  from  the  same  and  opposite  side; 
(b)  indirectly,  after  interruption  in  the  red  nucleus,  as 
the  rubro-thalamic  fibres. 

3.  Fibres  from  the  various  nuclei  by  way  of  the  median 
fillet,  i.e.,  (a)  from  the  gracile  and  cuneate  nuclei,  con- 
tinuing upward  the  paths  of  the  posterior  fasciculi  of  the 
•cord  after  decussation  for  the  most  part;  (b)  from  the 
jeception  nuclei  of  all  the  sensory  cranial  nerves,  as  well 


ANATOMY  63 

as  from  the  more  extensive  nuclei.      (See  Median  fillet 
connections.) 

4.  Probably  fibres  of  other  '^tracts  which  arise  within 
the  tegmental  area  of  the  brain-stem,  e.g.,  undemon- 
strated  fibres  from  the  posterior  longitudinal  fasciculus. 

5.  Fibres  from  all  parts  of  the  cerebral  cortex,  which 
pass  in  the  thalamic  radiation  as  cortifugal  paths. 

6.  Fibres  of  the  tractus  strio-thalamicus,  from  the 
caudate  nucleus  and  putamen.  Some  fibres  from  the 
caudate  nucleus  reach  the  thalamus  directly  by  way  of 
the  internal  capsule. 

7.  Fibres  as  a  strand  from  the  cortex  of  the  olfactory 
bulb. 

8.  Fibres  (thalamocipetal)  from  the  optic  tract,  and 
from  the  optic  radiation.  These  fibres  constitute  the 
stratum  zonale — a  layer  of  white  matter  on  the  superior 
aspect  of  the  thalamus.  The  fibres  from  the  lateral  root 
of  the  optic  tract  are  superficial,  and  cross  the  external 
geniculate  body  to  spread  over  the  thalamus.  The  fibres 
from  the  occipital  cortex,  by  way  of  the  optic  radiation, 
invest  the  pulvinar. 

9.  Fibres  of  the  stratum  zonale  from  the  temporal  cor- 
tex via  the  ventral  stalk. 

10.  Fibres  in  the  mammillo-thalamic  tract  being  a 
continuation  of  the  paths  leading  from  the  olfactory 
cortical  areas  in  the  uncus  and  hippocampus  to  the  mam- 
millary  nuclei. 

Efferent  paths,  i.e.,  from  the  thalamus. 

1.  Fibres — the  thalamo-cortical — which  issue  from 
the  latero-ventral  surface  of  the  thalamus,  and  proceed  to 
all  parts  of  the  hemisphere,  some  crossing  to  the  opposite 
side  by  way  of  the  corpus  callosum.  The  fibres  are  con- 
ventionally grouped  into  bundles,  called  the  stalks  of  the 
thalamus.  Each  stalk  is  named  according  to  its  rela- 
tions. Thus  there  is  a  frontal,  a  parietal,  an  occipital, 
and  a  ventral  stalk.  The  frontal  stalk  traverses  the 
internal  capsule  between  the  caudate  and  lenticular  nuclei, 
to  which  it  gives  fibres  and  ends  in  the  frontal  cortex. 
The  parietal  stalk  enters  the  internal  capsule,  and  fre- 
quently the  lenticular  nucleus  in  its  course  to  the  parietal 
cortex.     Other  fibres  destined  for  the  parietal  lobe  and 


64  SEMICIRCULAR  CANALS 

the  adjacent  parts  of  the  frontal  lobe,  are  continuations  of 
the  paths  of  the  mesial  fillet.  These  fibres  emerge  mostly 
from  the  ventral  tlialamic  nucleus,  pass  outward  to  the 
under  surface  of  the  lenticular  nucleus;  then,  bending 
upward,  traverse  the  lenticular  nucleus  by  way  of  the 
medullary  striae,  or  the  globus  pallidus  to  reach  the  cor- 
tex. Other  fibres  possibly  continue  the  fillet  path  by 
entering  the  internal  capsule,  and  thus,  perhaps,  reach 
the  coi-tex  directly.  The  occipital  stalk  connects  the 
thalamus  with  the  visual  cortical  areas  of  the  occipital 
and  parietal  lobes.  The  fibres  issue  from  the  lateral 
surface  of  the  pulvinar  and  as  the  optic  radiation  sweep 
outward  and  backward  around  the  posterior  horn  of  the 
lateral  ventricle  to  reach  the  cortex.  The  ventral  stalk 
emerges  from  the  fore  part  of  the  ventral  surface  of  the 
thalamus,  arising  from  the  lateral  and  mesial  nuclei.  It 
passes  dowTiward  and  outward  beneath  the  lenticular 
nucleus,  and  includes  two  systems  of  fibres.  Its  lower 
part — ansa  peduncularis — continues  laterally  into  the  cor- 
tex of  the  temporal  and  central  lobes.  Its  upper  part — 
ansa  lenticularis — skirts  the  adjacent  border  of  the  len- 
ticular nucleus,  which  it  enters  to  gain  the  putamen;  or, 
continuing  through  the  lenticular  nucleus  via  the  medul- 
lary laminse,  it  reaches  the  caudate  nucleus. 

The  efferent  fibres,  i.e.,  from  the  thalamus  are,  therefore: 

\.  To  the  frontal  cortex  and  to  the  caudate  and  len- 
ticular nuclei. 

2.  To  the  parietal  cortex  and  lenticular  nucleus. 

3.  Fibres  to  the  parietal  and  frontal  lobes  as  continua- 
tions of  the  paths  of  the  mesial  fillet  via  the  lenticular 
nucleus,  the  medullary  striae,  or  the  globus  pallidus  to 
the  cort<3X. 

4.  Fibres  that  possibly  continue  the  fillet  path  to 
reach  the  cortex  directly,  via  the  internal  capsule. 

5.  Fibres  to  the  cortex  of  the  occipital  and  parietal 
lobes. 

6.  Fibres  of  the  ventral  stalk,  (a)  to  the  cortex  of  the 
temporal  and  central  lobes  via  the  ansa  peduncularis ;  (b) 
to  the  putamen  as  fibres  of  the  ansa  lenticularis  through 
the  lenticular  nucleus,  or  to  the  caudate  nucleus  through 
the  lenticular  nucleus  and  the  medullary  laminae. 


ANATOMY  65 

7.  Fibres  in  the  thalamo-mammillary  tract,  the  paths 
possibly  being  continued  thence  to  the  olfactory  cortex  by 
way  of  the  anterior  pillar  of  the  fornix,  or  by  way  of  the 
mammillo-tegmental  strands  to  the  tegmentum  of  the 
mid-brain  and  to  lower  levels.  In  every  instance  where 
the  thalamus  is  connected  with  the  cortex,  i.e.,  where 
there  are  cortico-thalamic  paths,  there  are  also  paths  in 
the  reverse  direction,  i.e.,  thalamo-cortical  paths. 

The  epithalamus — a  subdivision  of  the  thalamencepha- 
lon — includes  the  trigonum  habenulse,  the  pineal  body, 
and  the  posterior  commissure. 

In  the  trigonum  habenulse  the  striae  mark  the  site  of 
the  taenia  thalami  and  the  still  deeper  ganglion  habenulse. 
The  source  of  the  fibres  of  the  striae  medullares  is  uncer- 
tain. 

Probable  constituents  of  the  striae  medullares. 

1.  Fibres — the  olfactory  habenular — arising  'from  the 
cells  within  the  septum  lucidum  and  the  olfactory  area. 

2.  Fibres — the  cortico-habenular — from  the  cortical 
cells  within  the  hippocampus  and  the  adjacent  area,  and 
by  way  of  the  fornix  and  its  anterior  pillar,  reaching  the 
fore  end  of  the  thalamus  to  pass  backward  within  the 
medullary  striae. 

Many  fibres  of  the  striae  medullares  end  about  the  cells 
of  the  ganglion  habenulse.  Some,  however,  reach  the 
pineal  body  through  the  peduncle  of  the  latter,  cross  in 
the  commissura  habenulae,  and  end  about  the  cells  of  the 
opposite  habenular  nucleus. 

The  ganglion  habenulae  in  turn  gives  origin  to  the 
fasciculus  retroflexus  of  Meynert,  which  arches  backward 
and  downward,  passing  between  the  central  grey  matter 
of  the  third  ventricle  and  the  thalamus  proper,  then  to 
the  mesial  side  of  the  red  nucleus  to  reach  the  base  of  the 
brain,  where  it  ends  about  the  cells  of  the  interpeduncular 
ganglion.  This  nucleus  is  a  well-defined  collection  of 
cells  in  many  animals.  In  man  it  consists  of  a  scattered 
median  cell  group  within  the  posterior  perforated  space, 
close  to  the  anterior  border  of  the  pons.  The  fasciculus, 
also  called  the  habenulo-peduncular  tract,  receives  fibres 
from  the  ganglion  habenulae  of  both  sides,  some  fibres 
having  crossed  in  the  habenular  commissure.     The  ma- 


66  SEMICIRCULAR   CANALS 

jority  of  its  nbres,  mostly  crossed,  end  in  the  interpedun- 
cular ganglion.  Many,  however,  may  be  traced  farther 
caudally  within  the  tegmentum  of  the  brain  stem  (Ober- 
steiner^^),  as  may  also  fibres  from  the  ganglion  inter- 
pedunculare. 

The  pineal  body  is  situated  just  over  the  superior  col- 
liculi.  Its  stalk  is  continuous  with  the  medullary  striae. 
The  body  contains  laminated  particles  of  carbonate  and 
phosphate  of  lime.  Structurally  it  resembles  the  inverte- 
brate visual  organ.     It  is  highly  developed  in  reptiles. 

The  posterior  commissure  (commissura  posterior  cere- 
bri) provides  paths  by  which  fibres  from  various  sources 
undergo  median  decussation.  It  is  a  small  cordlike  band 
of  white  matter  overlying  the  superior  entrance  of  the 
aqueduct  of  Sylvius.  It  is  partially  covered  by  the 
habenular  commissure  and  the  pineal  peduncle  above. 
Behind  and  laterally  it  is  continuous  with  the  superior 
colliculi.  It  is  present  in  all  vertebrates,  and  becomes 
myelinated  early  (Edinger  ^^) .  The  probable  constituents 
of  the  posterior  commissure  are : 

1.  Fibres  from  the  nucleus  of  the  posterior  commis- 
sure. 

2.  Fibres  from  the  nucleus  of  the  posterior  longitu- 
dinal fasciculus,  located  in  the  grey  matter  of  the  third 
ventricle  near  the  mammillary  bodies. 

3.  Fibres  from  the  posterior  tract  of  the  thalamus  of 
the  opposite  side,  which  descend  within  the  tegmentum, 
lateral  and  ventral  to  the  posterior  longitudinal  fasciculus. 

4.  Fibres  which  cross  to  join  the  fasciculus  retro- 
flexus. 

5.  Fibres  from  the  median  fillet. 

6.  Fibres  from  the  superior  cerebellar  peduncle  to  the 
thalamus  on  the  opposite  side. 

7.  Perhaps  fibres  from  the  deeper  grey  stratum  of  the 
corpora  quadrigemina  to  the  cerebral  cortex  of  the  oppo- 
site side. 

The  subthalamic  region  occupies,  on  each  side  of  the 
middle  line,  a  triangular  area  between  the  thalamus 
above  and  the  internal  capsule  and  its  prolongation — the 
crusta  of  the  peduncle — below.  It  is  a  link  between  the 
mid-brain  and  the  diencephalon,  and  contains  the  up- 
ward prolongation  of  the  tegmentum  of  the  cerebral  pedun- 


ANATOMY  67 

cles,  the  thalamocipetal  paths  of  the  fillet  and  of  the 
superior  cerebellar  peduncles,  the  upper  extremities  of 
the  substantia  nigra  and  of  the  red  nucleus,  and  a  new 
mass  of  grey  matter — the  corpus  subthalamicum. 

_The-  substantia  nigra  extends  through  the  mid-brain 
from  the  upper  borders  of  the  pons,  almost  to  the  level  of 
the  mammillary  body  in  the  subthalamic  region.  It 
separates  the  tegmentum  from  the  crusta  of  the  peduncles, 
and  contains  numerous  irregularly  scattered  nerve  cells, 
which  are  pigmented.  Along  its  ventral  border  lie  the 
nuclei  of  origin  of  the  third  and  fourth  nerves,  and 
within  its  lateral  parts  the  nuclei  of  the  mesencephalic 
roots  of  the  fifth.  The  functions  and  connections  of  the 
neurones  within  the  substantia  nigra  are  but  little  known. 

ProhabU  Connections  of  the  Siihstantia  Nigra 

Afferent  paths,  i.e.,  to  the  substantia  nigra. 

1.  Fibres  from  the  caudate  nucleus  and  the  putamen, 
and  perhaps  from  the  frontal  cortical  areas. 

Efferent  paths,  i.e.,  from  the  substantia  nigra. 

1.  Fibres  passing  into  the  tegmentum  and  the  crusta, 
and  thence  to  lower  levels. 

2.  Fibres  to  the  fillet  to  reach  the  superior  coUiculus 
(v.  Bechterew  ^3) . 

The  corpus  subthalamicum,  or  nucleus  of  Luys,  lies 
just  dorsal  to  the  crusta,  and  lateral  to  the  red  nucleus 
and  substantia  nigra.  Superiorly  it  extends  considerably 
beyond  the  red  nucleus,  and  consists  of  a  network  of  fine 
medullated  fibres,  enclosing  pigmented,  multipolar  nerve 
cells.  The  dorsal  surface  of  the  nucleus  is  defined  by  the 
overlying  lateral  parts  of  the  field  of  Forel,  which  consists 
of  a  stream  of  fibres  passing  between  the  red  nucleus  and 
the  thalamus  and  internal  capsule. 

Connections  of  the  Corpus  SuUhalamicum 

1.  Fibres  from  the  ventral  surface  of  the  nucleus, 
which  pierce  the  adjacent  crusta  and  join  the  ansa  len- 
ticularis  to  gain,  probably,  the  globus  pallidus. 

2.  Fibres — perforating — which    connect    the   nucleus 


68  SEMICIRCULAR  CANALS 

with  Meynert's  and  Gudden's  commissures  (Ober- 
steiner  ^^) . 

The  commissura  hypothalamica  traverses  the  floor  of 
the  third  ventricle  above  the  mammillary  bodies,  and  con- 
nects the  ventro-mesial  ends  of  the  two  subthalamic 
bodies. 

The  commissura  hypothalamica  contains  also: 

1.  Fibres — decussating — from  the  anterior  pillars  of 
the  fornix.  These  fibres  reach  the  mammillary  body  as  a 
crossed  tract. 

2.  Fibres  from  the  posterior  longitudinal  fasciculus 
(Edinger  ^^) . 

The  corpora  mammillaria  mark,  by  their  posterior 
surfaces,  the  anterior  limit  of  the  ventral  surface  of  the 
mid-brain.  Each  body  consists  of  an  outer  layer  of 
white  matter,  enclosing  a  core  of  grey  substance — ^the 
nucleus  mammillaris. 

Connections  of  the  Mammillary  Nucleus 

Afferent  paths,  i.e.,  to  the  nucleus. 

1.  Fibres  from  the  downward  arching  anterior  pillar 
of  the  fornix,  as  well  as  fibres  through  the  commissura 
hypothalamica  from  the  anterior  pillar  of  the  fornix  of 
the  opposite  side.  These  fibres  form  part  of  the  path 
connecting  the  cortical  olfactory  centres  in  the  uncus  and 
hippocampus  with  the  thalamus. 

2.  Fibres  to  the  mammillary  nucleus — as  the  thalamo- 
mammillary  tract  in  the  mammillo-thalamic  strand. 

3.  Possibly  fibres  from  the  posterior  longitudinal  fas- 
c  ^>ulus  by  way  of  the  hypothalamic  commissure. 

Efferent  paths,  i.e.,  from  the  nucleus. 

\.  Fibres — the  mammillo-thalamic  tract  or  bundle  of 
Vicq  d'Azyr — which  course  upward  and  forward  to  end 
in  the  anterior  nucleus  of  the  thalamus,  thus  completing 
the  path  connecting  the  cortical  olfactory  centres  of  the 
uncus  and  hippocampus  with  the  thalamus.  Beginning 
in  the  hippocampus  major  this  path  follows  the  fimbria, 
body,  and  antf3ri(jr  pillar  of  the  fornix  to  the  mammillary 
nucleus,  and  thence,  after  interruption,  proceeds  via  the 
mamniillo-tlialamic  strand  to  the  anterior  nucleus  of  the 


ANATOMY  69 

thalamus.  This  latter  strand  contains  fibres  running  in 
both  directions,  between  the  thalamus  and  the  mammil- 
lary  body. 

2.  Fibres  of  the  mammillo-tegmental  tract  which  arch 
backward  and  downward,  and  are  traceable  into  the  teg- 
mentum of  the  mid-brain  to  the  vicinity  of  the  inferior 
colliculli. 

3.  Fibres  of  the  pedunculus  corporis  mammillaris. 
These  constitute  another  mammillo-tegmental  tract. 
They  spring  from  the  lateral  mammillary  nucleus,  and 
course  backward  and  downward  along  the  medial  margin 
of  the  crusta  to  enter  the  tegmentum.  Their  destination 
is  not  known.  Kolliker  believes  they  end  in  the  central 
grey  matter  about  the  aqueduct  of  Sylvius,  near  the 
fourth  nerv^e  nucleus. 

4.  Strands  from  the  peripheral  layer  of  the  mammil- 
lary body  over  the  tuber  cinereum  (v.  Lenhossek  ^) . 

5.  Possibly  fibres  to  the  posterior  longitudinal  fascicu- 
lus by  way  of  the  hypothalamic  commissure. 

The  telencephalon  or  end-brain  consists  of:  (1)  the 
hemisphserium,  which  includes  the  pallium,  rhinencepha- 
lon,  and  corpus  striatum;  and  (2)  the  pars  optica  hypo- 
thalami, which  includes  the  lamina  cinerea,  optic  com- 
missure, tuber  cinereum,  and  pituitary  body. 

The  lamina  cinerea  consists  of  a  thin  layer  of  grey 
substance  extending  backward  above  the  optic  commis- 
sure, from  the  termination  of  the  corpus  callosum  to  the 
tuber  cinereum.  On  either  side  it  is  continuous  with  the 
grey  matter  of  the  anterior  perforated  space,  and  forms 
the  anterior  part  of  the  inferior  boundary  of  the  third 
ventricle.  It  connects  the  corpus  callosum,  and  is  some- 
times called  the  grey  root  of  the  optic  nerves  (Sappe^). 
The  functions  of  the  lamina  cinerea,  if  other  than  me- 
chanical, are  unknown. 

The  optic  chiasm  lies  in  the  optic  groove  of  the 
sphenoid  bone  in  front  of  the  tuber  cinereum,  and  beneath 
the  lamina  cinerea  with  the  anterior  perforated  space  on 
either  side. 

The  paths  of  optic  chiasm  are : 

1.  The  visual  fibres  proper  which,  in  animals  below 
the  rabbit,  e.g.,  guinea-pig,  fishes,  reptiles  and  most 
birds,   undergo   complete  decussation.     In  man  and  the 


70  SEMICIRCULAR   CANALS 

higher  animals  only  the  fibres  from  the  inner  portion  of 
each  retina  cross  in  the  chiasm  to  enter  the  opposite  optic 
tract.  Tlie  fibres  from  the  outer  side  of  the  retina  do  not 
decussate,  but  pass  into  the  optic  tract  of  the  same  side. 

2.  Fibres  that  pass  from  one  optic  tract  to  the  other 
along  the  posterior  border  of  the  chiasm  (Gudden's 
inferior  commissure) .  These  fibres — the  median  root  of 
the  optic  tract — connect  the  two  internal  geniculate  bodies, 
and  possibly  also  the  inferior  colliculi.  They  seem  related 
more  to  the  auditory  than  to  the  visual  system,  but  it  is 
possible  that  they  are  protective  reflex  paths. 

8.  Fibres  that  pass  from  the  chiasm  into  the  floor  of 
the  third  ventricle,  possibly  to  reach  the  third  nucleus. 
These  are  the  afferent  paths  for  pupil  constriction  (v. 
Bechterew  ^^) ,  but  this  view  seems  to  lack  the  support  of 
evidence  from  the  histological  structure  of  the  retina. 

4.  Fibres  along  the  anterior  margin  of  the  chiasm 
connecting  one  retina  or  optic  nerve  with  the  other  (com- 
missura  arcuata  anterior  of  Hannover;  bogen-commissure 
of  Stilling) .  Lesions  of  one  retina-  cause  degeneration  in 
the  opposite  optic  nerve,  due  to  the  presence  of  collaterals 
of  the  optic  nerve  which  course  backward  from  the 
chiasm  (Parsons  ^^), 

The  paths  in  the  optic  tract  are : 

1.  Fibres  in  the  lateral  root  constituting  the  greater 
part,  80%  in  maia,  of  the  optic  tract,  which  end  in  the 
extern^  geniculate  body,  the  paths  being  continued  to 
the  occipital  cortex  by  new  neurones  passing  in  the  tha- 
lamo-occipital  radiation  in  company  with  fibres  from  the 
pulviuar  a^nd  the  superior  colliculi  (optic  radiation  of 
Gratiolet) , 

2.  Fibres  to  the  thalamus  (pulvinar)  and  superior 
colliculi,  the  paths  being  continued  to  the  occipital  cortex 
by  fibres  that  pass  in  the  thalamo-occij^ital  radiation. 
Borne  of  the  fibres  from  the  pulvinar  and  external  genicu- 
late body  pass  as  main  stems  or  give  off  collaterals  on 
their  way  to  the  occipital  cortex.  Of  these  main  stems  or 
collaterals  some  go  to  the  corpus  striatum,  whilst  others 
descend  to  the  tegmentum  to  reach  the  cerebellum  prob- 
ably and  the  centres  and  motcjr  nuclei  of  the  muscles  of 
the   eyes,  head   and   neck.     These   are   the   fibres   most 


ANATOMY  71 

probably  that  mediate  the  physiological  nystagmus, 
which,  by  means  of  retinal  impressions,  facilitates  the 
visual  fixation  of  rapidly  passing  objects.  It  is  exceed- 
ingly probable  that  these  optic  pathways  are  closely 
related  functionally  to  the  labyrinthine  jDaths,  and  that  in 
many  instances  they  impinge  with  the  latter  on  the  same 
final  common  path.  In  the  lower  animals  the  optic  lobes, 
which  are  the  analogues  of  the  corpora  quadrigemina  in 
the  higher  animals,  are  the  main  visual  organs.  Almost 
all  the  optic  nerve  fibres  end  in  the  mesencephalic  nuclei 
(analogues  of  the  superior  colliculi)  and  in  the  dien- 
cephalic nuclei  (external  geniculate  bodies) .  This  latter 
is  the  first  evidence  of  real  visual  representation  in  the 
occipital  cortex  (Parsons^).  The  optic  nerve,  in  addition 
to  the  paths  already  mentioned,  has  fibres  w^hich  spring 
from  cells  situated  in  the  primary  optic  centres,  viz.,  the 
external  geniculate  bodies,  the  pulvinar,  and  the  superior 
colliculi.  Though  the  function  of  these  fibres  is  unknown, 
they  are  not  necessarily  centrifugal  paths  as  Parsons  sug- 
gests, but  may,  in  part,  represent  afferent  paths,  the  cell 
bodies  of  whose  neurones  lie  in  structures  central  to  the 
optic  tracts. 

It  may  be  observed  that  in  fishes  the  vestibular  nerve 
is  in  close  relation  w^ith  the  mesencephalic  centres 
(Loeb^^).  This  shows  that  the  mesencephalon  in  the 
lower  animals  at  least  probably  contains  important  coor- 
dinating centres  for  movements  of  station  and  equilibrium. 

The  tuber  cinereum  is  an  outpouching,  at  the  base  of 
the  brain,  of  a  thin  sheet  of  grey  matter,  an  extension  of 
that  surrounding  the  cavity  of  the  mid-brain  and  fourth 
ventricle.  It  contains  the  nucleus  tuberis  and  the  supra- 
optic nucleus.  The  connections  of  these  nuclei  are  un- 
knowm. 

The  rhinencephalon — the  oldest  part  of  the  hemisphere 
— includes  (1)  the  olfactory  lobe,  consisting  of  the  olfac- 
tory bulb,  the  olfactory  tract  and  roots,  the  olfactory 
trigone,  and  the  parolfactory  area;  (2)  the  uncus  and  a 
•number  of  accessory  parts.  The  fornix  is  the  chief  fibre 
tract  connecting  the  olfactory  cortex  in  the  uncus  and 
hippocampus  with  the  thalamus.  The  olfactory  cortex  is, 
therefore,  not  represented  in  the  corona  radiata,  but  has 
its  own  special  projection  fibres  in  the  cortico-mammillary 


72  SEMICIRCULAR   CANALS 

tract  within  the  fornix.  In  the  brain  the  sensory  paths 
are  the  first  to  acquire  the  myelin  sheath,  beginning  with 
those  of  smell  and  ending  with  those  carrying  auditory 
impulses  to  the  cortex.  By  observing  the  first  appearance 
of  the  myelin  sheath  in  various  paths,  the  olfactory  fibres 
have  been  traced  to  the  uncinate  gyrus,  whilst  the  auditory 
and  visual  fibres  have  been  traced  to  the  temporal  and 
occipital  lobes  respectively.  New  paths  have  similarly 
been  traced  from  the  areas  in  the  cortex  in  which  these 
sensory  fibres  terminate  down  to  the  medulla  and  motor 
nuclei  of  the  cord. 

Connections  of  the  Rhmencephalon 

Afferent  paths,  i.e.,  carrying  impulses  from  the  periphery. 

1.  To  the  thalamus  by  a  strand  from  the  cortex  of  the 
olfactory  bulb  to  the  antero- ventral  part  of  the  thalamus. 

2.  To  the  cortex  (a)  by  the  inner  olfactory  root, 
which  joins  the  mesial  aspect  of  the  anterior  extremity  of 
the  gyrus  fornicatus ;  (b)  by  the  outer  root  to  the  gyrus 
hippocampus. 

8.  Possibly  by  paths  from  the  posterior  longitudinal 
fasciculus,  by  way  of  the  hypothalamic  commissure  to 
the  mammillary  body. 

4.   Possibly  by  the  thalamo-mammillary  pathway. 

Efferent  paths. 

1.  From  the  cortex  by  the  cortico-mammillary  tract 
from  the  uncus  and  hippocampus  through  the  fimbria, 
body,  and  anterior  pillar  of  the  fornix  to  the  mammillary 
nuclei,  each  mammillary  body  receiving  fibres  from  the 
cortex  of  both  sides,  owing  to  a  decussation  in  the  com- 
missura  hypothalamica  of  some  fibres  from  the  anterior 
pillars  of  the  fornix.  From  the  mammillary  nuclei  the 
paths  are  continued  by  fibres  (A)  to  the  thalamus  by  the 
Vnammillo-thalamic  strand  or  bundle  of  Vicq  d'Azyr; 
and  (B)  to  the  tegmentum  of  the  mid-brain,  and  possiJDly 
to  lower  levels,  as  the  mammillo- tegmental  tracts,  of 
which  there  are:  (a)  The  mammillo-tegmental  tract 
proper,  the  fibres  of  which  have  been  traced  to  the  teg- 
mentum of  the  mid-brain  in  the  vicinity  of  the  inferior 
colliculi.       (b)     Possibly    a    mammillo-tegmental  tract 


ANATOMY  73 

through  the  pedunculus  corporis  mammillaris.  (c)  Pos- 
sibly fibres  to  the  posterior  longitudinal  fasciculus 
from  the  mammillary  body  via  the  hypothalamic  commis- 
sure. Such  a  connection  with  the  posterior  longitudinal 
fasciculus  would  be  a  possible  means  of  bringing  the 
olfactory  centres  into  relation  with  other  centres  in  the 
mid-brain,  pons,  and  medulla,  (d)  Possibly  strands 
connecting  the  mammillary  body  with  the  tuber  cine- 
reum. 

2.  From  the  thalamus,  (a)  The  thalamo-mammillary 
tract  may  be  an  efferent  path  from  the  thalamus,  along 
which  impulses,  received  directly  from  the  cortex  of  the 
olfactory  bulb,  may  pass  after  interruption  in  the  thala- 
mus. From  the  mammillary  body  the  path  is  continued 
by  way  of  the  mammillo-tegmental  paths,  or  perhaps 
through  the  posterior  longitudinal  fasciculus  to  other 
centres  in  the  mid-brain,  pons,  and  medulla,  which  are 
thus  brought  into  relation  with  the  olfactory  centres. 
(b)  Possibly  by  fibres  from  the  thalamus  to  other  portions 
of  the  cerebral  cortex,  and  perhaps  to  lower  centres  in  the 
brain-stem  and  cord. 

The  corpus  striatum  is  a  mass  of  grey  matter  supple-, 
mental  to  the  cortical  substance.  It  receives  fibres  con- 
veying sensory  impulses,  and  gives  off  fibres,  probably 
motor  in  function,  which  arise  from  its  cells. 

Connections  of  the  Corpus  Striatum 
Afferent  paths,  i.e.,  to  the  corpus  striatum. 

1.  By  way  of  the  tegmento-striate  fibres,  chiefly  con- 
tinued from  the  mesial  fillet,  and  perhaps  from  the  red 
nucleus  and  the  thalamic  region  via  the  internal  capsule, 
to  end  around  the  cells  of  the  putamen  and  head  of  the 
caudate  nucleus. 

2.  By  the  thalamo-striate  fibres,  which  pass  from  the 
thalamus  (a)  by  way  of  the  internal  capsule  to  the  caudate 
nucleus;  or  (b)  by  way  of  the  ansa  lenticularis  to  the 
putamen;  or  (c)  by  traversing  the  medullar}^  laminae  to 
the  caudate  nucleus. 

8.  By  cortico-striate  fibres.  Dejerine  denies  the  exist- 
ence of  these  paths,  but  Edinger  says  some  bundles  of 
fibres  can  be  demonstrated. 


74  SEMICIRCULAR   CANALS 

Efferent  paths,  i.e.,  from  the  corpus  striatum. 

1.  By  the  strio-thalamic  fibres,  consisting  of  (a)  those 
from  the  caudate  nucleus  to  the  thalamus  direct;  (b) 
those  which,  traversing  the  internal  capsule  and  medul- 
lary laminae  and  joining  fibres  from  the  putamen,  pass 
by  way  of  the  ansa  lenticularis  to  the  thalamus ;  (c)  those 
from  the  putamen,  which  reach  the  thalamus  partly  by 
way  of  the  globus  pallidus  and  partly  by  the  ansa  lenti- 
cularis. 

2.  By  the  strio-peduncular  fibres,  well  seen  in  the 
lower  animals  (Edinger) ,  as  the  continuation  of  the  basal 
tract  of  the  fore  brain.  The  fibres  pass  from  the  caudate, 
and  probably  from  the  lenticular  nucleus  into  the  subtha- 
lamic region  and  the  cerebral  peduncle,  joining  in  the 
latter  the  stratum  intermedium,  closely  related  to  the 
substantia  nigra. 

The  medullary  substance  of  the  brain  consists  of  fibres 
with  their  supporting  neuroglia.  The  fibres  are  of  three 
kinds,  viz.  (1)  association  fibres  linking  the  different 
portions  of  the  same  hemisphere  together,  and  which, 
with  the  exception  of  those  situated  about  the  fissure  of 
Rolando,  are  not  meduUated  at  birth;  (2)  commissural 
fibres;  and  (8)  projection  fibres. 

The  association  fibres  are  divided  into  the  short  and 
the  long.  The  short  association  fibres  stretch  from  one 
convolution  to  another,  some  loops — the  intracortical 
association  fibres — being  buried  in  the  grey  matter,  while 
others — the  subcortical  association  fibres — lie  in  the  adja- 
cent white  matter.  There  are  also  fibres  limited  to  con- 
volutions of  the  same  lobe,  the  intralobar  association 
fibres.  The  long  or  interlobar  association  fibres  include 
(1)  the  uncinate  fasciculus;  (2)  the  cingulum;  (8)  the 
superior  longitudinal  fasciculus;  (4)  the  inferior  longi- 
tudinal fasciculus;  and  (5)  many  other  long  association 
fibres  which  cannot  be  satisfactorily  demonstrated. 

The  uncinate  fasciculus  connects  the  orbital  surface  of 
the  frontal  lobe  with  the  anterior  portion  of  the  temporal. 
The  inferior  longitudinal  fasciculus  transmits  visual  im- 
pulses to  other  parts  of  the  cortex  (Dejerine) . 

The  anterior  commissure  contains: 

1.  Fibres  connecting  the  end  of  one  temporal  lobe 
with  the  end  of  its  fellow  of  the  opposite  side, 


ANATOMY  75 

2.  Fibres  from  one  olfactory  lobe  to  the  other. 

3.  Fibres  from  the  olfactory  lobe  on  one  side  to  the 
hippocampal  convolutions  of  the  opposite  side. 

4.  Fibres  from  the  olfactory  lobe  through  the  commis- 
sure to  reach  the  taenia  semicircularis,  and  to  proceed 
with  it  along  the  roof  of  the  inferior  horn  of  the  lateral 
ventricle  to  end  in  the  amygdaloid  nucleus. 

The  hippocampal  commissure  joins  the  two  hippo- 
campi. These  fibres  cross  in  the  psalterium,  and  some, 
after  decussation,  join  the  longitudinal  fibres  of  the  for- 
nix and  proceed  to  the  thalamus  via  the  mammillary 
body  and  mammillo-thalamic  strand. 

The  corpus  callosum — the  largest  commissural  tract  in 
the  brain — joins  the  t\^^o  hemispheres.  Little  is  known 
definitely  of  the  individual  fibre  paths  or  of  the  parts 
associated  through  them. 

The  projection  fibres  are  few  in  the  frontal,  parietal, 
and  latero-inferior  part  of  the  temporal  regions.  The 
function  of  these  areas  is  not  well  understood.  Flechsig 
believes  them  to  be  association  centres.  The  olfactory 
cortex,  as  before  stated,  is  not  represented  in  the  corona 
radiata,  having  its  own  projection  fibres  in  the  cortico- 
mammillary  tract  within  the  fornix. 

The  projection  tracts  are  divided  into  (1)  the  short; 
and  (2)  the  long. 

The  short  projection  tracts  include: 

1.  The  cortico-thalamic,  consisting  of  (a)  fibres  from 
the  frontal  lobe  to  the  anterior  end  of  the  thalamus;  (b) 
fibres  from  the  region  of  the  fissure  of  Rolando,  and  the 
adjoining  part  of  the  parietal  lobe  to  the  lateral  and 
mesial  nuclei  of  the  thalamus ;  (c)  fibres  from  the  occipi- 
to-temporal  region  to  the  medio-ventral  part  of  the  thala- 
mus ;  (d)  fibres  from  the  posterior  part  of  the  parietal 
lobe,  and  from  the  occipital  lobe  to  the  pulvinar. 

The  thalamo-cortical  tracts  are  associated  with  the 
foregoing.  They  leave  the  thalamus  as  its  stalks  or 
peduncles,  and  reach  the  various  areas  of  the  cortex. 
They  represent  continuations  of  the  sensory  paths  from 
the  cord,  brain-stem  and  cerebellum.  In  these  tracts  are 
represented  the  median  fillet,  the  spino-thalamic  tract, 
and  probably  part  of  Gowers'  tract  and  the  cerebello- 
rubro-thalamic  tract.     The  optic  radiation  represents  the 


76  SEMICIRCULAR  CANALS 

continuation  of  the  visual  paths  of  the  optic  tract  after 
interruption  in  the  pulvinar,  lateral  geniculate  bodies 
and  superior  colliculi. 

2.  The  cortico-geniculate  and  cortico-quadrigeminal 
tracts.  These  are  accompanied  by  corticipetal  fibres  from 
the  superior  colliculi  and  lateral  geniculate  bodies. 

3.  The  auditory  radiation  which  contains  cortifugal  as 
well  as  corticipetal  fibres  running  between  the  inferior 
coUiculus  and  median  geniculate  body  and  the  auditory 
centres  in  the  middle  portion  of  the  superior  temporal 
convolutions,  and  probably  the  adjoining  part  of  the 
operculum.  The  path  passes  through  the  retro-lenticular 
portion  of  the  posterior  limb  of  the  internal  capsule  be- 
neath the  lenticular  nucleus. 

4.  The  cortico-rubral,  which  is  a  supplementary  motor 
tract.  The  origin  of  these  fibres  is  probably  in  the  cortex 
of  the  parietal  lobe. 

The  long  projection  tracts  include: 

L  The  cortico-pontine.  The  continuation  of  these 
paths  after  interruption  in  the  pontine  nucleus  completes 
the  link  between  the  cerebral  cortex  and  the  cerebellum. 
The  cortico-pontine  tracts  include  (a)  the  fronto-pontine 
fibres;  and  (b)  the  temporo-occipito-pontine  fibres. 
Through  these  tracts  fibres  from  the  cerebral  cortex  of 
either  side  reach  the  cerebellum  on  both  sides. 

2.  The  motor  tracts  which  include : 

(a)  The  cortico-bulbar  tracts.  The  fibres  for  the 
movements  of  the  eye  muscles  spring  from  the  posterior 
portion  of  the  middle  frontal  convolution  (Mills  ^^),  ad- 
joining the  lower  part  of  the  precentral  gyrus,  in  which 
are  the  centres  for  the  cortico-bulbar  trar^ts.  The  exact 
location  of  the  strands  is  known  only  for  the  twelfth  nerve 
in  the  posterior  part  of  the  knee,  and  for  the  seventh, 
which  is  in  advance  of  the  twelfth.  Within  the  cerebral 
peduncle,  the  cortico-bulbar  strand  occupies  the  lateral 
part  of  the  inner  third  of  the  crusta,  and  the  fibres  for  the 
third  and  fourth  nerves  soon  turn  dorsally  and  cross  the 
raphe  to  end,  for  the  most  part,  in  the  nuclei  of  the 
opposite  side.  The  fibres  for  the  remaining  nuclei  pass 
near  the  middle  line,  and  cross  as  they  approach  the 
levels  of  the  nuclei  for  which  they  are  destined. 

(b)  The  cortico-spinal  tracts  or  pyramids^  occupy  the 


ANATOMY  77 

middle  third  of  the  crusta,  with  the  sensory  paths  on 
their  outer  side.  They  decussate  for  the  most  part  at  the 
lower  boundary  of  the  medulla.  The  fibres  that  do  not 
decussate  here  are  continued  down  the  cord  as  the  direct 
pyramidal  tracts,  but  they  also  cross  the  middle  line 
through  the  white  commissure  on  reaching  the  level  of 
their  destination,  although  there  is  evidence  tending  to 
show  that  part,  at  least,  of  these  fibres  do  not  cross  the 
middle  line.      (See  Pyramidal  tracts  in  the  cord. ) 

The  rolandic  region  is  concerned  in  sensation  as  well 
as  motion.  It  includes  the  precentral  and  postcentral 
convolutions  and  the  paracentral  lobe.  The  sensory  fibres 
from  the  periphery  to  this  area  carry  impulses  which 
excite  sensations  of  touch,  pain,  and  temperature,  as  well 
as  those  associated  with  impulses  from  the  muscles  and 
tendons,  and  possibly  those  associated  with  certain 
phases  of  acts  of  equilibration.  Excluding  the  sensori- 
motor and  the  various  sensory  areas,  about  two-thirds  of 
the  cerebral  cortex  has  no  known  connection  with  the 
periphery.  Flechsig  believes  these  regions  of  the  cortex 
to  be  association  centres.  The  motor  centres  are  mainly 
located  in  front  of  the  central  fissure.  Those  for  the  face 
and  tongue  are  in  the  lower  third  of  the  motor  zone.  In 
the  posterior  parts  of  the  second  frontal  convolution  and 
in  a  portion  of  the  third  frontal  convolution  are  the  cen- 
tres for  the  associated  lateral  movements  of  the  eyes,  and 
for  the  lateral  movements  of  the  head  (Beevor  and 
Horsley  ^) .  The  centres  for  stereognostic  perception  and 
muscular  sense  are  in  the  superior  and  inferior  parietal 
convolutions. 

The  speech  centres  in  right-handed  people  are  in  the 
posterior  part  of  the  third  left  frontal  convolution,  in  the 
first  left  temporal  convolution,  and  perhaps  in  the  left 
angular  gyrus.  Broca's  convolution — the  third  left  frontal 
— is  the  motor  speech  centre.  Destruction  or  disability 
of  this  centre  causes  motor  aphasia,  i.e.,  inability  to 
transform  concepts  into  words,  though  the  patient  be  con- 
scious and  the  tongue  capable  of  being  moved.  A  minor 
part  in  speech  is  played  by  the  posterior  part  of  the  right 
third  frontal  convolution,  but  it  is  the  chief  motor  centre 
in  left-handed  people. 

In  the  first  left  temporal  convolution  is  the  auditory 


78  SEMICIRCULAR  CANALS 

centre  for  speech.  Lesion  of  this  area  produces  loss  of 
memory  of  word-sounds,  though  the  hearing  in  the 
ordinary  sense  may  be  sufficiently  good.  Thus  distinction 
is  made  between  hearing  as  conceptualization  and  hearing 
in  the  ordinary  sense  of  becoming  conscious  of  sound  im- 
pressions originating  al)  externo.  A  similar  distinction 
holds  for  visual  acts,  and  as  we  shall  see  later,  there  is  a 
third  manner  in  which  individuals  "see"  and  probably 
also  hear  and  smell,  and  which  forms  the  basis  for  pro- 
tective reflex  acts  through  the  medium  of  centres  and 
paths  placed  below,  and  sometimes  widely  separated  from 
the  cerebral  cortex.  The  centre  for  memory  of  printed 
words  is  probably  in  the  left  angular  gyrus.  Lesions 
limited  to  this  region  are  rare.  They  render  a  person 
unable  to  understand  writing,  though  ordinary  vision  may 
be  good.  The  existence  of  a  motor  writing  centre  is 
doubtful  (Oppenlieim) ,  but  if  it  exists  it  is  probably 
located  in  the  posterior  portion  of  the  second  left  frontal 
convolution.  The  centre  for  smell  is  probably  somewhere 
near  the  anterior  portion  of  the  gyrus  fornicatus.  There 
is  no  definite  knowledge  about  the  location  of  the  cortical 
centre  for  taste.  The  auditory  centre  is  in  the  upper 
temporal  convolution.  Each  centre  is  probably  connected 
with  both  cochlear  nerves.  The  frontal  lobes  will  stand 
much  destruction  on  one  side  without  giving  rise  to 
marked  physical  signs.  This  has  been  frequently  noted 
in  experiments,  and  is  a  matter  of  common  clinical  ex- 
perience in  tumours  of  the  frontal  region,  where  the  chief 
symptoms  may  be  merely  hysteroid  manifestations. 

The  cuneus  and  calcarine  fissure — ^the  white  line  of 
Gennari — together  constitute  a  primary  and  lower  cortical 
or  visuo-sensory  centre.  The  lateral  aspect  of  the  occipi- 
tal lobe  is  a  visuo-psychic  area,  containing  subareas  or 
centres  concerned  in  higher  visual  processes.  Lesions  of 
the  lateral  occipital  lobe,  especially  if  large  and  in  the 
left  hemisphere,  or  lesions  on  both  sides,  cause  mind- 
blindness  analogous  to  word  deafness.  Lesions  of  the 
cuneo-calcarine  cortex  cause  lateral  homonymous  hemi- 
anopsia. This  may  also  be  produced  by  lesion  of  the 
lateral  part  of  the  occipital  lobe  if  it  extends  far  enough 
inward  to  interrupt  the  optic  radip^tions  (Schafer  and 
Brown  ^^) , 


ANATOMY  79 

Pathways  in  the  Spinal  Cord 

In  a  cross  section  of  the  cord  the  area  bounded  by  the 
posterior  median  sulcus  (dorsal  septum)  and  the  dorsal 
root  is  designated  as  the  posterior  funiculus,  the  area 
bounded  by  the  dorsal  and  ventral  roots  is  called  the  lat- 
eral funiculus,  and  that  bounded  by  the  ventral  root  and 
the  anterior  median  fissure  the  anterior  funiculus. 

The  term  fasciculus  is  intended  to  cover  any  fairly 
defined  bundle  of  fibres  connecting  one  centre  or  level  with 
another  centre  or  level,  without  intermption  of  the  path- 
way. A  fasciculus  consists  therefore  of  but  one  set 
of  neurones,  e.g.,  the  dorsal-spino-cerebellar  fasciculus 
(direct  cerebellar  tract) .  Tract  is  a  physiological  rather 
than  an  anatomical  term.  It  indicates  a  pathway  for  the 
conduction  of  impulses  without  regard  to  anatomical  in- 
terruptions. A  tract,  therefore,  may  consist  of  two  or 
more  sets  of  communicating  neurones,  forming  physio- 
logical continuity,  e.g.,  the  cerebello-vestibulo-spinal 
tract. 

The  term  column  is  now  reserved  by  many  authors  to 
designate  the  projections  of  grey  matter  within  the  white 
surrounding  substance,  e.g.,  the  ventral  grey  column 
(ventral  cornu),  the  dorsal  grey  column  (the  dorsal 
comu) . 

The  ascending  tracts  of  the  cord  include : 

1.  The  dorsal  fasciculi  (columns  of  Golland  Burdach). 

2.  The  dorsal  spino-cerebellar  fasciculus  (direct  cere- 
bellar tract,  or  tract  of  Flechsig) . 

3.  The  ventral  spino-cerebellar  fasciculus  (Gowers' 
tract) . 

4.  The  spino-tectal  and  spino-thalamic  tracts. 

5.  Helweg's  fasciculus  or  bundle. 

The  dorsal  fasciculi  consist  mainly  of  the  ascending 
arms  of  the  central  processes  of  the  dorso-spinal  or  pos- 
terior root  ganglia.  Cajal,  in  1889,  by  means  of  the  Golgi 
method,  demonstrated  the  bifurcation  of  the  posterior 
root  fibres  on  entering  the  cord.  In  animals  after  section 
of  the  dorsal  root  in  one  of  the  sacral  nerves,  it  was  seen 
by  means  of  the  Marchi  stain  that  a  great  part  of  the 
dorsal  fasciculi  (Burdach's  column  chiefly)  consisted  of 
the  descending  arms  of  the  T-bi furcations  of  the  posterior 


80  SEMICIRCULAR   CANALS 

root  fibres.  These  descending  arms  are  destined  for  lower 
segments  in  the  cord,  and  give  off  collaterals  at  various 
levels.  Some  of  them  constitute  long  pathways  for  spinal 
reflexes,  e.g.,  the  well-known  scratch  reflex  in  which  clonic 
movements  of  the  hind  leg  are  evoked  by  scratching  the 
region  behind  the  shoulder  of  the  normal  dog.  The  paths 
involved  in  this  reflex  have  been  demonstrated  by  Sher- 
rington and  Laslett^^  by  the  method  of  successive  de- 
generation, as  scattered  fibres  in  the  lateral  ground  bundles 
of  the  cord. 

The  ascending  arms  of  the  T-bifurcation  of  the  pos- 
terior nerve  roots  send  fibres  or  processes  and  collaterals 
to  the  different  segments  of  the  cord  at  various  levels. 
The  remaining  posterior  root  fibres  constitute  the  long 
ascending  paths  of  the  dorsal  fasciculi.  These  as  they 
ascend  are  gradually  displaced  toward  the  middle  line  and 
away  trom  the  grey  matter,  in  accordance  with  the  general 
law  of  the  eccentric  position  of  the  long  fibre  paths. 
Few,  if  any  collaterals  are  given  off  from  the  dorsal 
median  fasciculus  (Goll's  column) .  The  zone  of  Lissauer 
consists  of  the  bifurcation  of  the  finer  fibres  of  the  pos- 
terior nerve  root. 

The  terminations  of  the  fibres  and  collaterals  of  the 
posterior  nerve-roots  are  as  follows : 

1.  Some,  including  part  of  the  fibres  from  Lissauer's 
zone,  end  about  cells  in  the  substance  of  Rolando.  From 
this  point  the  pathway  is  continued  by  intermediate  neu- 
rones to  the  lateral  ground  bundle  and  so  to  the  cells  of 
the  grey  matter  of  other  segments. 

2.  Some  pass  directly  through  the  substance  of  Rolando 
to  terminate  in  tract  cells,  the  axones  from  which  pass  as 
the  spino-thalamic  tract  in  the  white  matter  of  the  same 
and  of  the  opposite  side.  The  fibres  that  cross  the  median 
line  pass  in  the  anterior  commissure. 

3.  Fibres  that  end  in  relation  with  the  ventral  horn 
cells  of  the  same  side  (reflex  paths).  Some  reflex  paths 
are  relayed  to  the  ventral  horn  cells  of  the  opposite  side. 

4.  Fibres  that  end  in  the  tract  cells  of  the  dorsal 
nucleus  and  in  other  cells,  the  axones  of  which  form  the 
dorsal  spino-cerebellar  fasciculus  (direct  cerebellar  tract) 
and  the  ventral  spino-cerebellar  fasciculus  (Gowers' 
tract) . 


ANATOMY  -  81 

5.  Some  fibres  enter  the  posterior  aspect  of  the  dorsal 
comu,  and  bend  upward  to  end  in  the  substance  of 
Rolando. 

6.  Some  fibres  of  the  dorsal  root  also  pass  in  the  pos- 
terior commissure  to  reach  the  cells  of  the  grey  matter  of 
the  opposite  side. 

The  collaterals  and  terminals  of  the  posterior  nerve 
root  may,  therefore,  terminate  in  any  part  of  the  grey 
matter.  The  collection  of  marginal  cells  (dorsal  nucleus) 
situated  near  the  mesial  surface,  close  to  the  base  of  the 
dorsal  cornu,  extends  from  the  cervical  to  the  first  and 
second  lumbar  segments,  and  is  known  as  the  column  of 
Clarke  (Clarke's  vesicular  column,  or  the  nucleus  of 
Stilling) .  From  these  cells  the  pathway  is  continued  by 
means  of  neurones  of  the  second  order  to  the  dorsal  spino- 
cerebellar fasciculus  (direct  cerebellar  tract)  of  the  same 
side,  and  so  to  the  vermis  of  the  cerebellum.  This  origin 
of  the  dorsal  spino-cerebellar  tract  has  recently  been  dis- 
puted, but  apparently  upon  insufficient  grounds.  It  must 
be  remembered,  however,  that  the  Golgi  stain  picks  out 
only  a  few  elements,  and  it  is  impossible  to  know  what 
elements  are  omitted.  The  small  cells  in  the  substance 
of  Rolando  also  send  axones  into  the  lateral  ground 
bundle. 

The  cells  of  origin  of  the  ventral  spino-cerebellar  tract 
are  not  definitely  known.  It  is  known,  however,  that 
some  fibres  of  this  tract  cross  in  the  anterior  commissure, 
and  it  is  probable  that  these  fibres  spring  from  cells  situ- 
ated in  the  dorsal  horn.  The  tract  does  not  degenerate 
after  section  of  the  dorsal  nerve  roots  (Mott) .  The  dorsal 
spino-cerebellar  fasciculus  is,  therefore,  an  uncrossed 
pathway,  whilst  the  ventral  spino-cerebellar  tract  is  both 
crossed  and  uncrossed.  Mott  believes  this  fasciculus  con- 
sists of  two  afferent  bundles,  one  of  which  the  ventral 
cerebellar,  situated  at  the  periphery,  passes  to  the  cere- 
bellum in  the  superior  peduncle,  whilst  the  other — the 
crossed  afferent  tract  of  Gowers  and  Edinger — passes  up 
on  the  outer  side  of  the  lemniscus  to  the  corpora-quadri- 
gemina  and  optic  thalamus  (Gordinier  ^^) .  The  spino- 
tectal and  spino-thalamic  tracts  spring  from  cells  about 
the  base  of  the  dorsal  cornu,  and  pass  up  on  the  inner 
side  of  the  ventral  spino-cerebellar  fasciculus  to  the  teg- 


82  SEMICIRCULAR   CANALS 

mentum  and  thalamus.  The  tracts  continue  the  paths  of 
the  posterior  nerve  root  of  the  opposite  side  mainly. 

The  fasciculus  of  Helweg  is  seen  only  in  the  upper 
cervical  cord.  Its  cells  of  origin  and  destination  are  un- 
known, although  it  has  been  assumed  that  the  path  is  in 
relation  with  the  inferior  olive. 

The  dorsal  fasciculi,  viz.,  the  fasciculus  gracilis  and 
the  fasciculus  cuneatus  (columns  of  Goll  and  Burdach) 
are  interrupted  in  the  posterior  nuclei  of  the  medulla,  the 
fasciculus  of  Goll  ending  in  the  nucleus  gracilis  and  that 
of  Burdach  in  the  nucleus  cuneatus.  The  fibres  from  these 
nuclei  for  the  most  part  cross  the  middle  line  as  the 
arcuate  fibres  about  the  level  of  the  upper  border  of  the 
pyramidal  decussation  in  the  lower  part  of  the  medulla 
oblongata.  This  sensory  decussation  marks  the  lowest 
limit  of  the  fillet,  the  fibres  of  which  continue  the  paths 
represented  in  the  dorsal  fasciculi.  (See  Connections  of 
the  fillet.) 

There  is  question  as  to  whether  some  of  the  component 
fibres  of  the  dorsal  fasciculi  are  directly  continued  to  the 
cerebellum  and  mesial  fillet  without  interruption  in  the 
posterior  nuclei  of  the  medulla.  Kolliker,  Solder,  Hoche, 
and  others  maintain  the  affirmative. 

The  dorsal  fasciculi  are  mainly  pathways  for  impulses 
related  to  the  so-called  deep  sensation  (muscle  and  ten- 
don) .  There  are  also  in  the  median  fibres  of  the  dorsal 
fasciculi  some  fibres  for  the  transmission  of  tactile  im- 
pulses. Some  authors  maintain  that  the  pathway  for 
tactile  sensation  is  uncrossed  and  interrupted  in  the  grey 
matter.  It  is  most  probable,  however,  that  the  paths  for 
tactile  sensation  are  both  crossed  and  uncrossed,  and  that 
in  the  dorsal  fasciculi  they  travel  to  a  variable  extent, 
many  passing  all  the  way  up  to  the  medulla  to  join  the 
mesial  fillet  after  interruption  in  the  posterior  nuclei  of 
the  medulla,  whilst  others,  after  travelling  a  variable  dis- 
tance, pass  into  the  grey  matter. 

The  dorsal  spino-cerebellar  and  the  ventral  spino-cere- 
bellar  paths  convey  those  afferent  unconscious  impressions 
that  underlie  coordination  and  cerebellar  muscle  tonus. 
The  dorsal  spino-cerebellar  path  is  uncrossed,  whilst  the 
ventral  spino-cerebellar  path  is  both  crossed  and  uncrossed. 
Both  pathways  are  interrupted  in  the  cord. 


ANATOMY  83 

The  spino-tectal  and  spino-thalamic  pathways  convey 
impulses  concerned  in  the  sensation  of  pain  and  tempera- 
ture and  to  some  extent  those  of  touch.  These  are  inter- 
rupted pathways  and  are  mainly  crossed  in  the  cord. 
They  join  the  mesial  fillet  above  the  sensory  decussation 
in  the  medulla. 

Helweg's  fasciculus  probably  conveys,  through  the 
inferior  olive  to  the  cerebellum,  impulses  akin  to  those 
that  travel  by  way  of  the  dorsal  and  ventral  spino-cere- 
bellar  pathways.  Some  fibres  of  the  ventral  spino-ce- 
rebellar  fasciculus  probably  reach  the  thalamus,  and 
perhaps  may  be  considered  as  stray  fibres  from  other  path- 
ways, e.g.,  spino-tectal,  spino-thalamic.  (See  Connections 
of  superior  and  middle  peduncles  of  the  cerebellum.) 
Gowers  believed  that  part  of  the  ventral  spino-cerebellar 
fasciculus  conveys  impulses  related  to  pain  and  tempera- 
ture. The  cerebellar  fibres  of  this  tract  pass  by  way  of 
the  inferior  and  superior  peduncles,  some  fibres  passing 
also,  according  to  Hoche,  by  way  of  the  superior  medul- 
lary velum.  The  fasciculus  has  been  traced  as  low  as  the 
fifth  lumbar  segment  (Mott,  ^°^  Russell  ^^^) ,  while  above, 
the  tract  was  traced  by  Rossolimo  ^^^  to  the  inferior  collic- 
uli,  substantia  nigra  and  the  globus  pallidus.  The  term 
Gowers'  tract,  as  originally  applied,  included  the  spino- 
thalamic and  spino-cerebellar  tracts.  At  the  present  time 
it  is  restricted  to  the  ventral  spino-cerebellar  fasciculus 
proper. 

Peripheral  Terminations  of  the  Affere^it  Paths 

The  afferent  or  sensory  paths  commence  at  the  periph- 
ery. The  bodies  of  the  afferent  peripheral  neurones  are 
separated  from  the  neural  tube,  and  are  located  in  the 
posterior  spinal  ganglia  or  their  analogues  in  the  cranial 
nerves.  The  first,  second,  and  eighth  cranial  nerves  have 
a  peripheral  apparatus  of  peculiar  structure. 

In  the  olfactory  nerve  the  primary  afferent  neurone  re- 
mains in  the  peripheral  epithelium.  In  the  eighth  nerve 
the  path  originates  in  the  neuro-epithelium,  but  the  cell 
body  remains  permanently  bipolar.  The  optic  nerve  is  in 
reality  not  a  nerve,  being  developed  from  an  invagination 
of  the  brain  wall. 


84  SEMICIRCULAR   CANALS 

The  peripheral  endings  of  the  sensory  neurones  are : 
1.   Free  endings,  in  which  the  nerve  fibres  lose  their 
medulla   and   end   between    (not  within)   the   epithelial 
cells  of  the  skin  and  mucous  membrane,  and  also  between 
the   connective-tissue    strata.      The   finer   threads   often 
terminate  in  end  knobs.     These  endings  are  believed  to 
be  the  receptive  organs  for  painful  stimuli. 
I       2.   Fibres  from  the  spinal  ganglia,  ending  in  the  sali- , 
vary  glands.     These  fibres  probably  constitute  part  of  the 
afferent  paths  for  the  reflex  increase  of  salivary  secretion. 
I       3.   Fibres  from  the  Gasserian  ganglion,  ending  in  the 
teeth  pulp. 

■  4.  Modified  forms  of  diffuse  termination,  e.g.,  the 
fibres  of  the  glosso-pharyngeal  ending  in  clusters  of  cells 
known  as  the  taste  buds  of  the  tongue.  Taste  buds  rep- 
resent endings  of  the  neuro-epithelial  type,  having  special 
connections  with  the  nerves,  e.g.,  wrappings  of  the  nerve 
fibres  about  the  taste-bud  epithelia.  It  is  believed  that 
these  accessory  structures  and  the  peculiar  disposition  of 
the  nerve  fibres  in  relation  to  them  render  the  nerve  fibres 
accessible  to  certain  kinds  and  degrees  of  stimuli  only. 

5.  Touch  cells.  In  the  simplest  form  the  nerve  fibres 
form  a  cuplike  expansion  for  the  reception  of  one  end  of  a 
single  cell.  This  form  represents  the  beginning  of  the 
development  of  Meissner's  corpuscles,  the  second  stage  of 
which  is  represented  by  the  nerve  fibres  forming  a  flat 
disc-like  expansion  containing  neuro-fibrils  between  two 
epithelial  cells.  These  endings  are  found  in  the  papillae 
of  the  skin  and  in  other  parts  of  the  body. 

6.  End  bulbs,  consisting  of  a  granular  core  of  cells 
surrounded  by  connective-tissue  lamellae,  the  nerve  fibre 
ending  in  a  snarl  of  fibrillse  twisted  about  the  core. 
These  endings  are  in  the  conjunctiva,  glans  penis,  serous 
membranes,  mesentery,  etc. 

7.  Corpuscles  of  Vater-Pacini.  These  bodies  consist 
of  a  capsule  composed  of  crescentic  lamellae  which  are 
covered  with  endothelial  plates.  Inside  the  capsule  is  the 
core  containing  cells  and  naked  axis  cylinders.  These 
corpuscles  are  always  located  deeply,  e.g.,  in  the  deeper 
portions  of  the  connective-tissue  layer  of  the  skin  of  the 
palmar  and  plantar  aspect  of  the  fingers  and  toes,  in  the 
pancreas,  and  in  the  mesentery.     They  are  assumed  to  be 


ANATOMY  85 

Organs  adapted  for  heavy  pressure  stimuli,  whilst  Meiss- 
ner's  corpuscles  are  looked  upon  as  the  organs  for  lighter 
pressure  sensation. 

8.  In  tendons  the  Golgi-Mazzini  organs,  which  consiert 
of  rich  arborizations  of  nerve  fibres,  forming  varicosities 
between  the  tendon  fibres,  the  whole  being  enclosed  in  a 
connective-tissue  capsule.  These  organs  aid  in  the  per- 
ception of  the  position  and  movement  of  the  limbs  in 
space. 

9.  Muscle  spindles  which  are  modified  muscle  fibres, 
receiving  a  special  nerve  ending.  These  are  widely  dis- 
tributed in  the  body  and  are  probably  present  in  all 
skeletal  muscles.  They  are  especially  numerous  in  the 
small  muscles  of  the  hand  and  foot.  None  have  been 
found  in  the  intrinsic  muscles  of  the  tongue,  nor  in  the 
eye  muscles,  although  in  the  tendons  of  the  latter  Golgi- 
Mazzini  organs  have  been  demonstrated.  Each  spindle 
consists  of  a  capsule  composed  of  half  a  dozen  concentric 
layers  of  fibrous  tissue,  enclosing  a  group  of  from  three  to 
ten  or  more  muscle  fibres  with  medullated  nerves,  blood- 
vessels, and  interspersed  connective  tissue.  The  muscle 
fibres  of  the  spindle  are  embryonic  in  structure,  having 
more  nuclei  than  the  ordinary  muscle  fibres,  and  contain- 
ing some  undifferentiated  sarcoplasm.  Sherrington  has 
shown  that  these  structures  are  afferent  in  function,  since 
they  do  not  degenerate  after  section  of  the  motor  nerves. 

10.  It  is  still  a  question  as  to  whether  sensory  im- 
pulses from  the  periphery  pass  into  the  cord  by  way  of 
afferent  sympathetic  fibres  that  enter  the  posterior  spinal 
ganglia. 

The  descending  paths  in  the  cord  include : 

1.  The  pyramidal  tracts  consisting  of  (a)  the  crossed 
or  lateral  cerebro-spinal  fasciculus;  (b)  the  uncrossed  or 
mesial  cerebro-spinal  fasciculus. 

2.  The  tecto- spinal  tract. 

3.  The  rubro-spinal  tract. 

4.  The  tract  from  the  interstitial  nucleus  of  Cajal. 

5.  The  tract  from  Deiters'  nucleus. 

6.  The  tract  of  Thomas. 

7.  The  septo-marginal  tract. 

8.  The  comma  tract  of  Schultze. 

The  fibres  of  the  pyramidal  tracts  end  about  the  cells 


86  SEMICIRCULAR   CANALS 

of  the  ventral  horn  (ventral  grey  column).  Some  ob- 
servers, however,  believe  they  terminate  about  the  cells  of 
the  intermediate  grey  matter,  the  impulses  being  relayed 
by  short  neurones  to  the  ventral  horn  cells.  It  is  often 
stated  that  all  the  fibres  of  the  direct  pyramidal  tract 
cross  the  median  line  at  their  levels  of  destination,  but 
this  point  cannot  be  considered  as  proven,  since  lesion  of 
the  direct  pyramidal  tract  causes  some  impairment  of 
function  in  the  muscles  on  the  side  of  the  lesion.  More- 
over, even  in  the  crossed  pyramidal  tracts,  there  are  some 
homo-lateral,  i.e.,  uncrossed  fibres. 

The  fibres  of  the  tecto-spinal  tract  spring  from  the 
roof  of  the  mid-brain.  After  decussation  the  fibres  pass 
downward  into  the  cord,  where  they  lie  according  to  some 
observers  near  the  ventral  sulcus,  whilst  according  to  other 
observers,  they  are  scattered  through  the  antero-lateral 
ground  bundle.  The  fibres  are  believed  to  end  in  relation 
with  the  ventral  horn  cells.  The  presence  of  any  tecto- 
spinal fibres  in  the  cord  has  been  disputed. 

The  fibres  of  the  rubro-spinal  tract  (von  Monakow's 
tract)  spring  partly  from  cells  in  the  red  nucleus  located 
in  the  tegmentum  of  the  mid-brain,  and  partly  from  other 
cells  in  the  formatio  reticularis  in  the  region  of  the  pons. 
The  path  is  mainly  crossed.  In  the  cord  the  tract  lies 
ventral  to  the  lateral  pyramidal  tract,  its  fibres  partly 
mingling  with  those  of  the  latter.  The  fibres  of  the 
rubro-spinal  tract  end  in  the  dorsal  part  of  the  ventral 
horn.  This  tract  is  part  of  an  important  cerebellar  effer- 
ent path,  composed  of  three  sets  of  neurones,  viz.:  (1) 
from  the  cerebellar  cortex  to  the  nucleus  dentatus;  (2) 
from  the  nucleus  dentatus  to  the  red  nucleus ;  (3)  from 
the  red  nucleus  (rubro-spinal  tract  proper)  to  the  ventral 
root  c(3lls.  As  previously  stated,  owing  to  a  double 
decussation,  viz.,  in  the  superior  peduncles  and  in  the 
rubral  neurones  of  the  rubro-spinal  tract,  efferent  cere- 
bellar impulses,  transmitted  via  the  cerebello-rubro-spinal 
tract,  are  mainly  distributed  to  the  ventral  root  cells  of  the 
homo-lateral  side. 

The  tract  from  the  interstitial  nucleus  of  Cajal  is  un- 
crossed and  lies  near  the  ventral  sulcus.  Its  fibres 
terminate  in  the  ventral  horn,  some  having  been  traced 
into   the   lumbar   region   of   tlie   cord.     The  interstitial 


ANATOMY  87 

nucleus  of  Cajal  is  located  in  the  formatio  reticularis  of 
the  tegmentum  of  the  mid-brain  anterior  (cephalad)  to 
the  III  nucleus.  The  fibres  of  this  tract,  however,  are 
believed  by  some  to  originate  in  the  nucleus  of  Darksche- 
witsch,  and  by  others  in  the  nucleus  of  the  posterior 
longitudinal  fasciculus,  and  by  still  others  in  the  nucleus 
of  the  posterior  commissure.  It  is  a  question  whether 
any  of  these  nuclei  is  identical  with  the  interstitial 
nucleus  of  Cajal. 

The  tract  from  Deiters'  nucleus  occupies  the  ventral 
and  mesial  periphery  of  the  cord.  The  more  lateral  fibres 
are  imcrossed,  w^hilst  those  near  the  ventral  sulcus  spring 
from  the  nuclei  on  both  sides.  It  is  probable  that  with 
the  fibres  of  this  tract  other  fibres  descend  from  other 
portions  of  the  vestibular  nucleus,  and  from  other  nuclei 
in  the  formatio  reticularis  grisea  of  the  medulla  (reticulo- 
spinal fibres).  The  fibres  all  terminate  in  the  ventral 
horn  cells. 

As  previously  stated,  Deiters'  nucleus  is  an  important 
relay  station  for  afferent  labyrinthine  impulses  to  the 
cerebellum.  It  is  possible  that  Deiters'  nucleus  may 
serve  as  an  immediate  coordinating  centre  for  labyrinthine 
impulses ;  but  for  reasons  often  reiterated  in  the  preceding 
pages  this  is  highly  improbable  in  man  and  the  higher 
animals,  in  whom  the  chief  coordinating  centres  for  laby- 
rinthine impulses  are  located  in  the  cerebellimi  and  pos- 
sibly in  the  mid-brain.  On  the  other  hand,  Deiters' 
nucleus  receives  fibres  from  the  cerebellum  and  relays  the 
paths  dow^n  the  cord.  Again  some  fibres  from  Deiters' 
nucleus,  probably  the  continuation  of  vestibular  paths, 
pass  to  the  homo-lateral  inferior  olive,  and  directly,  or 
after  interruption,  pass  to  the  contra- lateral  olive  which 
sends  numerous  fibres  to  the  cerebellum  via  the  inferior 
peduncle  (restiform  body).  The  inferior  olive  and 
Deiters'  nucleus  are  thus  in  intimate  relation  with  the 
cerebellum  by  means  of  afferent  and  efferent  paths.  The 
afferent  vestibular  paths  from  Deiters'  nucleus  to  the 
nucleus  fastigii  are  mainly  crossed.  The  efferent  cere- 
bellar paths  from  the  nucleus  fastigii  to  Deiters'  nucleus 
are  also  mainly  crossed,  but,  as  many  of  the  fibres  of  the 
vestibulo-spinal  tract  near  the  ventral  sulcus  are  crossed, 
provision  is  thereby  made  for  bringing  each  half  of  the 


• 


I 
I 

a 

I 
I 


I5 


ANATOMY  89 

cerebellum  into  functional  relationship  with  the  homo- 
lateral half  of  the  body  by  means  of  a  double  decussation, 
as  in  the  case  of  the  cerebello-rubro-spinal  paths. 

For  reasons  previously  stated,  it  is  perhaps  better  to 
call  the  vestibulo-spinal  tract  the  cerebello-vestibulo- 
spinal  tract  and  the  vestibulo-olivary  tract  the  vestibulo- 
olivo-cerebellar  tract.  (See  Vestibular  connections. )  All 
the  fibres  of  the  tract  from  Deiters'  nucleus,  taken  collec- 
tively, are  sometimes  called  the  antero-lateral  descending 
tract  or  the  marginal  bundle  of  Lowenthal. 

The  tract  from  the  interstitial  nucleus  of  Cajal  and  the 
mesial  portion  of  the  tract  from  Deiters'  nucleus  consti- 
tute the  major  portion  of  the  descending  fibres  of  the 
median  longitudinal  fasciculus  an  important  bundle  in 
the  segmental  brain.  Some  observers  hold  that  some 
fibres  from  the  cerebellum  pass  down  the  cord  without 
interruption  in  Deiters'  nucleus. 

The  fibres  of  the  tract  of  Thomas  originate  in  the 
formatio  reticularis  of  the  medulla,  and  pass  downward  in 
the  lateral  column,  to  end  in  the  grey  matter  of  the 
cervical  cord. 

The  septo-marginal  tract  is  a  small  bundle  of  fibres 
lying  next  to  the  posterior  septum.  In  the  sacral  cord  it 
forms  a  small  dorso-medial  triangle,  whilst  in  the  lumbar 
region  it  forms  a  superficial  bundle,  and  the  oval  bundle 
of  Flechsig  at  the  middle  of  the  posterior  septum.  In 
the  thoracic  and  cervical  regions  the  fibres  are  scattered. 
The  fibres  of  this  tract  are  probably  the  descending  axones 
of  cells  in  the  cord,  forming  short,  intersegmental  (spino- 
spinal) tracts. 

The  "comma"  tract  of  Schultze  consists  of  a  small 
bundle  of  descending  fibres,  lying  about  the  middle  of 
the  posterior  column.  It  is  a  well-marked  feature  of  the 
dorsal  cord.  The  fibres  probably  spring  from  the  column 
cells  of  the  grey  matter  of  the  cord,  forming  short  inter- 
segmental (spino-spinal)  tracts,  although  they  are  believed 
by  some  to  be  descending  branches  of  the  dorsal  root 
fibres. 

Many  descending  tracts  contain  also  ascending  paths. 

The  peripheral  terminations  of  the  efferent  paths  are : 

1.  The  motor  end  plates  of  striated  muscle.  These 
consist  of  flattened  expaijgions  of  undifferentiated  sa^rcQ^ 


90  SEMICIRCULAR   CANALS 

plasm.  Here  the  nerve  fibres  ramify  in  close  relation 
with  the  muscle  fibre.  It  is  a  question  whether  the  nerve 
terminals  are  located  outside  or  inside  the  sarcolemma. . 
Section  of  the  motor  nerve  fibre  is  followed  by  atrophy  of 
the  muscle. 

'  2.  Axones  which  form  the  preganglionic  fibres  of  the 
sympathetic  nervous  system.  These  axones  always  end^ 
in  a  sympathetic  ganglion.  From  this  point  the  path- 
ways are  continued  by  the  axones  of  spnpathetic  neurones 
(post-ganglionic  fibres  of  Langley) ,  to  end  in  the  muscle 
of  the  intestines,  blood-vessels,  heart,  etc.,  or  in  the 
glands,  etc. ,  of  the  skin.  In  glands  the  fibres  end  about 
the  lumen.  Some  endings  occur  in  the  follicular  cells  of 
the  ovary  but  none  reach  the  ovum  itself.  In  the  kidney 
the  endings  are  mainly  in  the  walls  of  the  blood-vessels. 
There  are  peripheral  ganglia  in  the  plexuses  of  Auerbach 
and  Meissner,  situated  between  the  coats  of  the  gastro- 
intestinal tract,  mainly  in  the  small  intestine.  These 
ganglia,  which  are  not  of  the  sympathetic  type  (Lang- 
ley^),  contain  multipolar  cells  the  dendrites  of  which 
lie  in  the  connective-tissue  layers.  There  are  also,  in  the 
stroma  of  the  mucous  membrane,  cells  from  which  fibres 
pass  between  the  epithelial  cells.  The  spinal  pregan- 
glionic fibres  become  pilo-motor,  vaso-motor,  or  secretory 
fibres,  according  as  their  post-ganglionic  continuations 
end  in  the  erector  muscles  of  the  hairs,  in  the  muscles  of 
the  blood-vessels,  or  in  the  sweat-glands,  etc.  It  is  prob- 
able that  some  sympathetic  afferent  paths  reach  the  pos- 
terior spinal  ganglia.  In  the  heart  muscle  the  sympa- 
thetic fibres  ramify  and  often  end  in  expansions. 

The  central  nei-vous  system  may  be  divided  into  (1)  a 
segmental  part,  comprising  the  spinal  cord  and  the  basal 
part  of  the  brain;  and  (2)  a  suprasegmental  part,  com* 
prising  the  expanded  portions  of  the  dorsal  wall  of  the 
neural  tube,  viz.,  the  pallium,  corpora  quadrigemina 
and  cerebellum  (Bailey ''^^'''). 

Tracts  which  connect  one  region  of  the  cord  or  seg- 
mented brain  with  another  region  are  known  as  interseg- 
mental tracts,  whilst  tracts  that  pass  to  or  from  the  supra- 
segmental parts  are  called  suprasegmental  tracts.  The 
intersegmental  tracts  are  mainly  located  in  the  antero- 
lateral ground  buiajdle.  close  to  the  grey  matter^  some  being; 


'    ANATOMY  91 

found  also  in  the  ventral  portion  of  the  posterior  columns 
(oval  bundle,  etc. ) . 

The  existence  of  reflex  spino-spinal  paths  is  shown  by 
the  familiar  extensor-thrust  reflex  described  by  Sherring- 
ton.^' In  a  spinal  dog,  slightly  stroking  the  skin  behind 
the  plantar  cushion  with  the  edge  of  a  piece  of  paper,  or  . 
pushing  the  finger-tip  between  the  plantar  cushion  and  the 
toe-pads  causes  the  leg  on  that  side  to  extend  powerfully 
for  a  short  period.  The  pathway  for  this  reflex  is  via  the 
posterior  root  fibres  direct  to  the  ventral  horn  cells  of  the 
same  side.  The  stimulation  passes  to  neurones  which 
innervate  all  the  extensor  muscles  of  the  leg  and  there  is 
but  one  synapsis  between  the  afferent  fibres  and  the  body 
and  dendrites  of  the  efferent  neurones.  Reference  to  the 
schalt-zellen  of  v.  Monakow,  which  are  probably  interposed 
between  the  afferent  and  efferent  neurones,  is  omitted  for 
the  sake  of  simplicity. 

The  extensor  thrust  reflex  is  probably  an  important 
element  in  the  reflex  mechanism  of  locomotion.  In  cer- 
tain cases  irritation  of  the  foot  causes  extensor  thrust  in 
the  opposite  leg.  Here  an  intermediate  spino-spinal 
neurone  carries  the  stimulus  to  the  ventral  horn  cells  of 
the  opposite  side.  In  this  reflex,  therefore,  three  neu- 
rones are  involved,  viz. :  (1)  An  afferent  peripheral;  (2) 
a  heteromeric  spino-spinal  neurone;  and  (3)  an  efferent 
neurone 

Longer  spino-spinal  neurones  have  been  shown  to 
exist  by  means  of  the  scratch  reflex.  The  pathway  for 
this  reflex  is  a  long  and  uncrossed  one.  The  fibres  of  the 
intermediate  neurones  actually  involved,  lie  scattered  in 
the  lateral  part  of  the  lateral  column,  i.e.,  in  the  lateral 
ground  bundle,  as  demonstrated  by  Sherrington  and 
Laslett^^  in  the  following  manner:  The  cord  was  tran- 
sected between  the  second  and  third  thoracic  segments. 
This  caused  degeneration  of  all  fibres  entering  the  cord 
from  the  brain,  mid-brain,  bulb,  and  cervical  and  first 
and  second  thoracic  segments.  The  dog  was  kept  alive 
for  one  year,  which  allowed  time  for  complete  degenera- 
tion of  the  severed  tract  and  for  absorption  of  the 
products  of  degeneration.  The  cord  was  then  transected 
again  between  the  fourth  and  fifth  thoracic  segments  and 
the  secondary  degeneration  in  the  divided  tracts  studied 


92  SEMICIRCULAR   CANALS 

by  the  ordinary  methods,  e.g.,  Marchi,  etc.  By  means  of 
this  method  of  "successive  degeneration"  the  scratch 
reflex  chain  was  shown  to  consist  of  (1)  a  receptive  neu- 
rone from  the  skin  to  the  spinal  grey  matter  of  the  corre- 
sponding spinal  segment  for  the  shoulder;  (2)  a  long 
descending  proprio-spinal  neurone  from  the  grey  matter 
of  the  shoulder  segment  to  that  of  the  leg  segments  via 
the  lateral  part  of  the  lateral  column;  (8)  a  motor 
neurone  to  a  flexor  muscle. 

This  chain  has  three  neurones,  enters  the  grey  matter 
twice,  and  has  two  synapses  exclusive  of  the  schalt-zellen. 
The  motor  neurone  is  the  final  common  path  the  rest  of 
the  arc  being  afferent  (Sherrington^^). 

The  efferent  paths  of  the  cord  convey  impulses  which 
may  be  grouped  as  follows : 

1.  Motor,  including  (a)  voluntary  and  reflex  motor, 
muscle  tonus,  etc. ;  (b)  vaso-motor;  (c)  viscero-motor; 
(d)  cardio-m.otor;  (e)  pilo-motor. 

2.  Secretory  to  the  various  glands — gastric,  salivary, 
pancreatic,  sweat,  etc. 

3.  Inhibitory  for  each  of  the  foregoing. 

The  impulses .  conveyed  in  the  afferent  paths  of  the 
cord  may  be  grouped  as : 

1.  Sensory,  including  all  impulses  affecting  conscious 
perception,  e.g.,  visual,  auditory,  olfactory,  gustatory 
pressure,  pain,  temperature,  hunger,  thirst,  etc. 

2.  Reflex,  including  those  impulses  which  evoke 
various  motor  and  secretory  reactions.  The  impulses 
which  originate  in  the  specialized  nervous  structures  of 
the  semicircular  canals  and  vestibule  of  the  internal  ear 
fall  within  this  group. 

3.  Inhibitory.  Little  is  known  definitely  of  the 
nature  of  the  impulses  of  this  group. 

It  has  not  been  demonstrated  that  afferent  impulses 
inhibit  conscious  sensations,  although  unconscious  re- 
flexes, e.g.,  sneezing  may  in  some  cases  be  inhibited  by 
afferent  impulses  (Howell  ^^). 

The  impulses  that  originate  in  the  semicircular  canals 
and  vestibule  of  the  internal  ear  can  unquestionably 
inhibit  certain  efferent  motor  (tonus)  paths,  as  may  be 
seen  in  cold  irrigations  of  the  external  auditory  canal, 
and  in  Qertain  forms  of  rotation.     But  this  effegt  ^hQwld 


ANATOMY  93 

in  some  instances  be  classed  as  a  depression  of  function 
in  the  afferent  elements  of  the  ordinary  reflex  tonus  mech- 
anisms, rather  than  as  an  instance  of  positive  inhibition. 
This  subject  will  be  discussed  more  fully  in  a  later 
chapter. 

The  tonus  of  the  muscles  of  the  body  is  partly  main- 
tained by  a  constant  stream  of  afferent  impulses  from  the 
periphery  to  the  related  cells  in  the  ventral  horns  and  in 
other  centres  of  coordination  and  tonus,  e.g.,  the  cerebel- 
lum, mesencephalic  centres,  etc. 

The  grouping  of  the  various  cells  in  the  ventral  horn 
has  only  been  partially  determined  in  regard  to  their 
functions.  The  ventral  group  is  probably  related  to  the 
long  flexors  and  extensors  of  the  limbs  and  the  central 
group  to  the  muscles  for  the  finer  movements  of  the 
fingers  and  toes.  In  the  third  to  the  fifth  cervical  seg- 
ments the  central  group  contains  the  cells  related  to  the 
phrenic  nerve.  The  dorsal  mesial  group  seems  to  be 
related  to  the  muscles  of  the  vertebral  column.  Extra 
groups  of  cells  are  found  in  the  dorso-lateral  region. 
These  cells  are  probably  related  to  the  muscles  of  the 
limbs. 

Touch,  pain  and  temperature  are  grouped  as  super- 
ficial sensibility,  as  compared  with  muscle  and  tendon 
sense  and  deep  pressure,  w^hich  are  classed  as  deep  sensi- 
bility. 

Head  and  Rivers  ^^  have  found  in  the  skin  two  systems 
of  sensory  fibres.  One  system,  the  protopathic,  is  related 
to  sensations  of  pain  and  of  extreme  changes  of  tempera- 
ture. The  sensations,  however,  are  imperfectly  localized, 
and  the  sensibility  is  low,  i.e.,  the  threshold  of  stimula- 
tion is  high.  The  kind  of  sensation  present  in  the 
viscera,  also  mediated  by  this  system  of  nerve  fibres,  is 
called  protopathic  sensibility,  and  may  be  regarded  as  a 
defensive  agency  against  pathological  changes.  It  com- 
prises sensations  of  pain,  of  heat  above  37°  C,  and  of 
cold  not  above  26°  C.  It  is  assumed  that  three  different 
sets  of  nerve  fibres  mediate  each  of  these  three  sensa- 
tions. 

The  second  system  of  fibres,  the  epicritic,  mediates 
sensations  from  light  pressures  and  from  small  differences 
in  temperature  between  26°  and  37°  C. 


94  SEMICIRCULAR   CANALS 

Epicritic  fibres  regenerate  much  more  slowly  after 
lesions  than  protopathic  fibres.  They  enable  us  to  make 
exact  discriminations  of  touch  and  temperature.  They 
are  found  only  in  the  skin,  and  include  separate  fibres  for 
heat,  cold,  tactual  localization  and  tactual  discrimina- 
tion. 

Some  authors  assume  that  the  peculiar  structure  of  the 
various  sensory  terminals  (receptors)  have  much  to  do  in 
determining  the  adequate  stimulus  for  the  various  nerve 
fibres ;  and,  indeed,  there  is  evidence  that  the  doctrine  of 
specific  nerve  energies  applies  to  the  cutaneous  senses, 
i.e.,  that  each  sense  has  its  own  nerve  fibres  capable  of 
mediating  only  its  own  quality  of  sensation. 

There  is  also  evidence  that  the  peripheral  terminals  of 
the  efferent  paths  (effectors)  determine  the  effect  of  effer- 
ent impulses.  Thus  Langley^^  caused  fibres  from  the 
chorda  tympani,  which  are  vaso-dilators  (inhibitory)  for 
the  submaxillary  gland,  to  grow  down  into  the  peripheral 
end  of  the  divided  cervical  sympathetic,  which  carries 
vaso-constrictors  for  the  same  gland,  and  found,  after 
regeneration  had  taken  place,  that  stimulation  of  the 
chorda  tympani  then  caused  vaso-constriction  in  the  sub- 
maxillary gland.  Erlanger^  cut  the  fifth  cervical  nerve, 
and  sutured  the  proximal  stump  to  the  distal  stump  of 
the  sectioned  vagus.  Later  he  found  that  stimulation  of 
the  fifth  trunk  caused  typical  vagus  phenomena. 

In  the  following  pages  we  shall  have  occasion  to  revert 
to  this  subject,  when  it  will  be  shown  that  the  ampullary 
nerve  terminals  of  the  semicircular  canals  and  of  the 
maculae  acusticse  of  the  vestibule  may  be  affected  by 
various  forms  of  stimulation,  e.g.,  galvanic,  thermic, 
rotation  and  always  with  the  same  constant  specific 
result. 

Recapitulation  of  the  Cerebellar  Paths 
Afferent  cerebellar  tracts,  i.e.,  to  the  cerebellum. 
Paths  through  inferior  peduncle 

1.  By  way  of  the  vestibular  reception  nuclei  (includ- 
ing Deiters')  to  the  roof  nucleus  of  the  opposite  side. 
Mainly  crossed. 


ANATOMY  95 

2.  By  way  of  the  vestibulo-olivo-cerebellar  tract. 
Mainly  crossed. 

8.  Dorsal  spino-cerebellar  fasciculus  (direct  cerebellar, 
or  tract  of  Flechsig) .     Mainly  uncrossed. 

4.  The  ventral  spino-cerebellar  fasciculus  (Gowers' 
tract).     Partly  crossed. 

5.  Arcuate  fibres  from  the  nuclei  of  the  posterior 
tracts;  partly  crossed;  and  some  fibres  from  the  arcuate 
nucleus,  partly  crossed. 

6.  Olivo-cerebellar  fibres;  mainly  crossed.  These 
fibres  include  the  vestiMlo-olivo-cerebellar  tract  for  part 
of  its  extent.      (See  2  above.) 

7.  Fibres  from  the  nucleus  lateralis;  partly  crossed. 

8.  Nucleo-cerebellar  tract;  mostly  crossed.  This  tract 
includes  No.  1  above,  as  well  as  the  fibres  formerly  in- 
cluded under  the  term  direct  sensory  cerebellar  tract  of 
Edinger. 

9.  Fibres  from  the  third  nucleus  to  the  opposite  half 
of  the  cerebellum  (v.  Bechterew). 

Paths  through  the  middle  peduncle 

10.  Fronto-  and  temporo-occipito-cerebellar  tracts. 
Mainly  crossed. 

11.  Possibly  collaterals  from  the  pyramidal  tracts — - 
mainly  crossed. 

Paths  through  the  superior  peduncle 

12.  Some  fibres  of  the  ventral  spino-cerebellar  fasci- 
culus (Gowers'  tract) ;  mainly  crossed  (Gordinier ''^) . 

18.  Fibres  from  the  red  nucleus  to  the  dentate  nucleus ; 
mainly  crossed. 

Through  undefined  paths 

14.  Fibres  from  various  sources,  bringing  various 
centres  of  the  brain-stem,  medulla  and  cord  into  relation 
with  each  other  under  one  common  coordinating  centre; 
fibres  from  the  eyes  directly  or  indirectly,  whereby  these 
aid  in  the  maintenance  of  equilibrium  through  the  opera- 
tion of  the  cerebellum.  The  fibres  from  the  eyes  include 
pupillary  paths  (v.  Bechterew  ^^) ,  but  this  point  can  hardly 
be  considered  as  settled.  Other  fibres  are  supposed  to 
bring  the  visceral  movements  under  cerebellar  control, 


96  SEMICIRCULAR   CANALS 

though  it  is  probable  that  the  cerebelhim  exerts  but  little 
direct  control  upon  visceral  movements.  These  fibres  are 
said  by  some  anatomists  to  pass  in  the  dorsal  spino-cere- 
bellar  tracts.  Fibres,  especially  those  from  the  various 
organs  of  special  sense,  convey  impressions  from  the  audi- 
tory, vestibular,  visual  and  olfactory  organs  to  the  cere- 
bellum. 

Efferent  cerebellar  tracts,  i.e.,  from  the  cerebellum. 

By  way  of  the  inferior  peduncle 

1.  Part  of  the  cerebello-olivary  fibres,  the  paths  being 
continued  into  the  anterior  ground  bundle  of  the  cord 
(Kolliker).  The  destination  of  the  fibres  is  uncertain, 
but  most  probably  it  is  the  ventral  horn-cells. 

2.  The  cerebello-vestibulo-spinal  tract.  Uncrossed 
probably  because  of  double  decussation.  (See  Vestibulo- 
spinal tract  in  the  cord. ) 

Through  the  middle  peduncle 

3.  The  cerebello-rubro-spinal  fibres.  Relations  mainly 
uncrossed  because  of  a  double  decussation. 

4.  The  cerebello-ponto-pyramidal  or  cerebello-pyra- 
midal  fibres.  Relations  uncrossed  because  of  a  double 
decussation. 

Through  the  superior  peduncle 

5.  The  cerebello-tegmental  tract,  which  includes  (a) 
the  cerebello-thalamo-cortical  paths  crossed  and  uncrossed ; 
(b)  the  cerebello-rubro-thalamico-cortical  paths,  partly 
crossed;  (c)  the  cerebello-rubro-spinal  tract  proper,  the 
relations  of  which  are  mainly  uncrossed  because  of  a 
double  decussation. 

6.  Fibres  to  the  oculo-motor  nuclei  of  the  opposite 
side  (v.  Bechterew  ^^) .  These  fibres  are  concerned  prob- 
ably in  the  conjugate  movements  of  the  eyes. 

Through  undefined  paths 

7.  Fibres  to  the  posterior  longitudinal  fasciculus. 

8.  Fibres  to  the  various  centres  in  the  mid-brain, 
pons,  medulla,  and  cord,  which  insure  coordinated  action 
of  ocular,  skeletal  and  perhaps  of  the  visceral  muscles  as 


ANATOMY  97 

well  as  of  the  great  centres  in  the  medulla,  e.g.,  the  vagus, 
glosso-pharyngeal  vaso-motor,  respiratory,  etc. 

Marchi  traced  degenerating  fibres  from  the  cerebellum 
to  all  the  cranial  nerves,  but  Ferrier  and  Turner,  ^  as  well 
as  Risien-Russell,  have  not  been  able  to  confirm  his  find- 
ings. 


CHAPTER  VI 

THE   SYMPATHETIC   OR   AUTONOMIC   NERVOUS 

SYSTEM 

The  sympathetic  or  autonomic  nervous  system  (Lang- 
ley)  is  comi)osed  of  neurones,  the  cell  bodies  of  which  lie 
in  various  sympathetic  ganglia.  The  chief  of  these 
ganglia  are : 

1.  The  s}Tnpathetic  chain  from  the  superior  cervical 
to  the  ganglion  coccygeum. 

2.  The  outlying  ganglia,  ¥/ith  or  without  names,  but 
related  to  the  former  group  as  follows :  (a)  In  the  abdo- 
men; the  prevertebral  ganglia,  viz.,  the  semilunar  or 
coeliac,  from  which  arises  the  coeliac  plexus  and  the 
inferior  mesenteric  giving  rise  to  the  hypogastric  nerve. 
These  ganglia  lie  ventral  to  the  sympathetic  chain,  but 
are  in  direct  connection  with  it.  (b)  In  the  region  of 
the  head  other  ganglia  of  the  same  type  are  found,  viz., 
the  ciliary,  spheno-palatine,  otic,  submaxillary,  sublin- 
gual, etc.  To  these,  perhaps,  should  be  added  the  cardiac 
ganglia  and  those  ganglia  located  in  the  plexuses  of 
Meissner  and  Auerbach  between  the  coats  of  the  intestinal 
tube,  although  Langley  ^Moelieves  that  the  cells  of  the 
ganglia  of  the  Meissner  and  Auerbach  plexuses  are  not  of 
the  sympathetic  type. 

The  continuity  of  the  sympathetic  with  the  central 
nervous  system  is  effected  by  efferent  fibres  which  leave 
the  latter  for  the  most  part  by  way  of  the  anterior  spinal 
nerve  roots,  or  their  analogues  in  the  cranial  nerves.  It 
is  possible  that  some  efferent  fibres  may  leave  the  cord  by 
way  of  the  posterior  nerve  root.  Such  fibres,  however, 
must  suffer  interruption  in  the  dorsal  root  ganglia  which 
contain  some  sympathetic  cells,  since  they  do  not  degen- 
erate after  section  of  the  posterior  nerve  root.  Cf.  the 
antidromic  impulses  of  Bayliss.'*^ 

98 


ANATOMY  99 

The  efferent  paths  from  the  central  nervous  system 
are,  in  every  instance,  interrupted  once  at  least  in  the 
sympathetic  ganglia.  From  the  point  of  interruption  the 
pathway  is  continued  by  synrpathetic  neurones  to  the 
peripheral  tissues.  The  sympathetic  j^^thway  consists 
therefore  of  two  or  more  neurones,  one  of  which  belongs 
to  the  central  nervous  system,  constituting  the  pregangli- 
onic fibre.  The  path  is  completed  by  the  post-ganglionic 
fibre  that  springs  from  a  cell  of  one  of  the  sympathetic 
ganglia.  "The  fibres  from  the  S23inal  cord  to  the  sympa- 
thetic ganglia  connect  certain  cells  of  the  spinal  cord  with 
the  cells  of  the  sympathetic  ganglia  in  the  same  way  as 
the  fibres  of  the  pyramidal  tracts  connect  certain  cells  of 
the  brain  with  the  cells  of  the  spinal  cord.  These  spinal 
fibres  become  pilo-motor,  vaso-motor,  or  secretory  fibres, 
according  as  the  fibres  from  the  sympathetic  cells,  with 
which  they  are  connected,  end  in  the  erector  muscles  of 
the  hairs,  muscles  of  the  blood-vessels,  or  in  the  sweat- 
glands"  (Langley^^).  The  sympathetic  system  is  also 
connected  with  the  central  nervous  system  by  means  of 
afferent  pathways  which  pass  by  way  of  the  posterior 
root  ganglia,  forming  the  afferent  path  for  ceii:ain  re- 
flexes, and  exceptionally,  perhaps,  for  conscious  sensa- 
tions. 

The  sympathetic  reflexes  in  the  normal  individual 
are  carried  on  below  the  level  of  consciousness,  but  in 
certain  disordered  states,  e.g.,  neurasthenia,  cardiac  pal- 
pitation, disorders  of  digestion,  etc.,  afferent  influences 
from  the  sympathetic  system  reach  the  level  of  conscious 
perception. 

The  preganglionic  fibres  of  the  sympathetic  system 
spring  from  four  regions,  viz. :  (1)  From  the  mid-brain, 
emerging  in  the  third  cranial  ner^^e,  and  passing  to  the 
ciliary  ganglion;  (2)  from  the  bulbar  region,  emerging 
in  the  seventh,  ninth,  tenth,  and  eleventh  cranial  nerves; 
(8)  from  the  thoracic  nerves,  viz. ,  from  the  first  thoracic 
to  the  fourth  or  fifth  lumbar  nerves  and  passing  in 
general  to  the  s}mipathetic  chain,  many  fibres,  however, 
passing  without  interruption  to  the  abdominal  ganglia; 
(4)  from  the  sacral  regions  by  way  of  the  nervous  erigens 
supplying  the  descending  colon,  rectum,  anus  and  geni- 
tal organs. 


100  SEMICIRCULAR  CANALS 

The  connections  between  the  anterior  nerve  roots  and 
the  chain  of  sympathetic  ganglia  are  known  as  the  rami 
communicantes.  These  are  divided  into  (a)  white  rami, 
or  those  possessing  a  medullary  sheath  and  which  consist 
of  preganglionic  fibres;  and  (b)  grey  rami,  which  are 
non-medullated,  or  are  but  slightly  medullated  and  con- 
sist of  post-ganglionic  fibres.  In  the  cervical,  lumbar 
and  sacral  regions,  the  rami  are  exclusively  grey  whilst  in 
the  thoracic  and  upper  lumbar  regions  both  white  and 
grey  rami  are  found.  The  fibres  of  the  white  rami 
(preganglionic  fibres)  may  pass  up  or  down  the  chain  for 
some  distance  before  ending  in  a  sympathetic  ganglion. 

The  grey  rami  represent  post-ganglionic  fibres  return- 
ing from  the  sympathetic  chain  to  join  the  anterior 
spinal  nerves,  which  they  accompany  to  their  areas  of 
distribution,  especially  the  cutaneous  areas,  since  the 
branches  to  the  skin  supply  the  sweat-glands,  blood-ves- 
sels and  pilo-motor  muscles. 

The  paths  which  pass  as  post-ganglionic  fibres  in  the 
grey  rami  to  any  one  spinal  nerve  do  not  necessarily  rep- 
resent continuations  of  the  paths  that  pass  as  pregan- 
glionic fibres  in  the  white  rami  from  the  same  nerve.  In 
general,  there  is  a  great  outflow  of  preganglionic  fibres, 
including  vaso- motor,  secretory  (sweat)  and  pilo-motor 
in  the  white  rami  from  the  first  and  second  thoracic  to 
the  second,  and  even  to  the  fourth,  lumbar  nerve.  The 
continuations  of  those  paths  destined  for  the  skin  areas  of 
the  head,  limbs,  and  trunk,  return  by  the  grey  rami  to 
the  anterior  spinal  nerves  and  run  with  them  to  their 
destination. 

The  fibres  for  the  blood-vessels,  glands  and  walls  of 
the  abdominal  and  pelvic  viscera,  after  entering  the  sym- 
pathetic chain,  emerge  without  suffering  interruption,  and 
pass  still  as  preganglionic  fibres  of  the  splanchnic  nerves, 
to  the  coeliac  ganglion,  or  in  the  branches  that  connect 
with  the  inferior  mesenteric  ganglion.  From  these  points 
the  paths  are  continued  as  post-ganglionic  fibres. 

The  fibres  for  the  glands,  blood-vessels  and  plain 
muscle  of  the  head  region  after  entering  the  sympathetic 
chain  pass  upward  along  the  cervical  sympathetic  to  end 
in  the  superior  cervical  ganglion.  From  this  point  the 
paths   are    continued    by   postganglionic   fibres,    which 


ANATOMY  101 

emerge  in  the   various   plexuses   that   spring  from   this 
ganglion. 

The  course  of  the  various  preganglionic  fibres  is  as 
follows : 

1.  Those  from  the  third  cranial  nerve  end  in  the  cil- 
iary ganglion,  thence  the  path  is  continued  as  postgangli- 
onic fibres  that  pass  in  the  short  ciliary  nerves  to  the 
iris  and  ciliary  muscle. 

2.  The  fibres  that  emerge  by  the  VII  and  IX  cranial 
nerves  probably  supply  the  glands  and  blood-vessels  (vaso- 
dilator fibres)  of  the  mucous  membrane  of  the  nose  and 
mouth.  Some  of  these  fibres  reach  the  fifth  nerve  by 
anastomosing  branches  and  are  distributed  with  it. 

The  preganglionic  fibres  of  the  VII  and  IX  cranial 
nerves  end  in  the  ganglia  of  the  sympathetic  type  of  this 
region,  viz. ,  the  spheno-palatine,  otic,  submaxillary,  sub- 
lingual. 

3.  The  preganglionic  fibres  of  the  X  cranial  nerve 
(representing  also  fibres  from  the  X  nucleus)  are  viscero- 
motor for  the  oesophagus,  stomach,  small  intestine,  and 
large  intestine  as  far  as  the  descending  colon.  They  also 
supply  motor  fibres  for  the  bronchial  musculature,  inhibi- 
tory fibres  for  the  heart,  and  secretory  fibres  for  the  gas- 
tric and  pancreatic  glands.  It  is  well  known  that  the 
central  nervous  system  can  inhibit  and  augment  the  gen- 
eral contractions  of  the  stomach  and  intestines. 

The  ganglia  in  which  the  preganglionic  fibres  of  the 
vagus  end  have  not  been  definitely  located,  but  probably 
these  comprise  the  small,  and  for  the  most  part  unnamed 
ganglia  distributed  in  and  near  the  organs  innervated. 

Burton- Op itz  *^  has  demonstrated  by  means  of  the 
strohmur  that  the  vagus  contains  no  vaso-motor  fibres  for 
the  stomach. 

4.  The  preganglionic  fibres  from  the  sacral  cord  pass 
in  the  anterior  roots  of  the  second  to  the  fourth  sacral 
nerves.  The  branches  from  these  roots  unite  to  form  the 
nervus  erigens  (pelvic  nerve)  which  loses  itself  in  the 
pelvic  plexus  without  connecting  with  the  sympathetic 
chain.  The  pelvic  plexus  is  also  formed  in  part  from  the 
hypogastric  nerve  arising  from  the  inferior  mesenteric 
ganglion.  Through  this  pathway  sympathetic  fibres  from 
the  upper  lumbar  region  enter  the  plexus. 


102  SEMICIRCULAR   CANALS 

The  sympathetic  fibres  of  the  nervus  erigens  supply 
vaso-dilator  fibres  to  the  external  genitals  causing  erec- 
tion in  the  male.  They  also  supply  vaso-dilator  fibres  to 
the  rectum  and  anus,  and  motor  fibres  to  the  plain  muscle 
of  the  descending  colon,  rectum  and  anus.  The  pregan- 
glionic fibres  of  these  pathways  end  in  small  sympathetic 
ganglia  in  the  pelvic  plexus  or  in  the  neighborhood  of  the 
organs  supplied. 

The  accelerator  fibres  for  the  heart  emerge  from  the 
anterior  roots  of  the  second,  third  and  fourth  thoracic 
spinal  nerves  (according  to  some  authorities  from  the 
first  and  fifth  thoracic,  and  even  from  the  lower  cervical 
nerve  roots  as  well) .  The  fibres  pass  by  the  white  rami 
to  the  stellate  or  first  thoracic  ganglion,  some  ending  in 
the  inferior  cervical  ganglion,  and  thence  by  way  of  the 
annulus  of  Vieussens  to  the  inferior  cervical  ganglion. 
Many  branches  leave  the  sympathetic  system  and  vagus 
in  this  region  and  pass  to  the  cardiac  plexus  and  so  to 
the  heart.  Hence  in  some  of  these  branches  accelerator 
fibres  are  found  mixed  with  vagus  inhibitory  fibres.  No 
accelerator  fibres  are  found  in  the  cervical  sympathetic 
above  the  inferior  cervical  ganglion.  The  vagus  contains 
some  accelerator  fibres  as  stimulation  of  that  nerve  after 
atropin  causes  acceleration  of  the  heart. 

The  accelerator  centre  has  not  been  definitely  located. 
Stimulation  of  the  upper  cervical  region  causes  cardiac 
acceleration,  but  this  merely  shows  that  the  centre  may  be 
situated  in  this  region  or  above  it. 

Certain  nerve  fibres  carry  afferent  impulses  to  the  vaso- 
motor centres  whereby  reflex  constriction  or  dilatation  of 
the  peripheral  vessels  is  effected  with  consequent  tendency 
to  elevation  or  lowering  of  the  general  blood-pressure. 
Such  fibres  are  known  as  pressor  or  depressor  nerves  re- 
spectively. In  the  dog  the  afferent  depressor  fibres  for 
the  heart  run  in  the  vagus,  but  in  other  animals  these 
fibres  form  a  separate  bundle — the  depressor  nerve — dis- 
covered by  Ludwig  and  Cyon  in  1866.  In  man  the 
depressor  fibres  most  probably  run  in  the  vagus,  and 
originate  between  the  cardiac  muscle  fibres  or  in  the  walls 
of  tlie  aorta.  These  fibres  are  merely  sensory,  and, 
when  stimulated,  cause  inhibition  of  the  vaso-constrictor 
centre. 


ANATOMY  103 

The  normal  mode  of  stimulation  of  the  sympathetic 
system  is  reflex.  This  portion  of  the  nervous  system  is, 
therefore,  mainly  concerned  with  involuntary  action. 
Apparently  the  only  reason  that  can  be  assigned  for  this 
fact  is  that  the  ultimate  points  of  origin  of  the  paths  are 
located  in  regions  other  than  the  voluntary  motor  cortex 
(Howell  ^^) .  However,  as  before  stated,  in  certain  abnor- 
mal conditions  afferent  impulses  from  the  sympathetic 
system  may  give  rise  to  conscious  sensations.  Animals, 
as  Goltz  and  others  have  shown,  live  after  severance  of 
the  nerve  connections  of  the  abdominal  viscera  with  the 
spinal  cord.  After  some  primary  disturbances  the  func- 
tions of  the  alimentary  canal  go  on  as  usual,  but  the  gen- 
eral vital  resistance  is  much  impaired,  necessitating  great 
care  in  the  preparation  and  selection  of  food.  This 
indicates  that  whilst  the  cerebro-spinal  system  normally 
exerts  control  over  intestinal  movements,  and  presumably 
over  other  visceral  functions,  the  latter  nevertheless  can 
be,  and  perhaps  normally  are,  mainly  executed  under  the 
influence  of  mechanisms  belonging  to  the  diffuse  as  dis- 
tinguished from  the  cerebro-spinal  nervous  system.  Bay- 
liss  and  Starling  ^^  concluded  that  peristalsis  is  a  compli- 
cated reflex  carried  out  through  the  intrinsic  ganglia. 

Summary  of  the   Vaso-motor  Nerves 
Efferent  fibres  : 

1.  Vaso-constrictor  fibres  distributed  chiefly  to  the 
skin  and  the  abdominal  viscera  (splanchnic  area) .  The 
blood-vessels  of  this  area  are  all  governed  by  the  general 
constrictor  centre  in  the  medulla  as  well  as  by  their  own 
particular  centres  in  the  cord  or  elsewhere.  They  are 
normally  in  a  state  of  tonic  contraction. 

2.  Vaso-dilator  fibres,  distributed  especially  to  erectile 
tissue,  glands,  the  bucco-facial  regions  and  muscles. 
The  blood-vessels  of  these  structures  and  areas  are  not 
under  the  control  of  a  superior  governing  centre  in  the 
medulla,  and  the  dilator  fibres  are  not  normally  in  a  state 
of  tonic  activity. 

Afferent  fibres : 

1.  Pressor  fibres  which  cause  a  rise  in  blood-pressure 


104  SEMICIRCULAR   CANALS 

by  reflex  stimulation  of  the  vaso-constrictor  centres,  e.g., 
sensory  nerves  of  the  skin  or  any  sensory  nerve  when 
powerfully  stimulated. 

2.  Depressor  fibres  which  cause  vaso-dilatation  and 
fall  of  blood-pressure  by  inhibition  of  the  vaso-constrictor 
centre  in  the  medulla  oblongata,  e.g.,  depressor  fibres  of 
the  heart. 

8.  Depressor  reflex  vaso-dilator  fibres  which  cause 
vaso-dilatation  and  fall  in  blood-pressure  by  stimulation 
of  the  related  vaso-dilator  centres,  e.g.,  erectile  tissue, 
congestion  of  glands  in  functional  activity. 


CHAPTER  VII 

THE  PATHS   INVOLVED   IN  PUPILLARY  MOVEMENTS 

The  mechanism  of  pupillary  constriction  consists 
chiefly  in  contraction  of  the  sphincter  muscle  accompanied 
by  relaxation  of  the  dilator  and  dilatation  of  the  blood- 
vessels. Dilatation,  on  the  other  hand,  is  effected  mainly 
by  contraction  of  the  dilator  muscle,  accompanied  by 
inhibition  of  the  sphincter  and  contraction  of  the  vessels 
of  the  iris.  The  part  played  by  the  blood-vessels  is  a 
relatively  unimportant  factor,  as  it  has  been  shown 
(Budge  and  Waller  ^^^)  that  dilatation  can  occur  without 
variation  in  the  blood-supply  of  the  iris,  whilst  Sal- 
kowski  '^^  showed  that  actual  constriction  of  the  vessels 
may  accompany  pupillary  dilatation.  Langley  and  An- 
derson, ^^  however,  state  that  constriction  of  the  arteries 
with  contraction  of  their  longitudinal  fibres  might  be  a 
possible  factor  in  dilatation,  but  do  not  believe  that  vas- 
cular changes  have  much  influence  on  pupillary  move- 
ments. 

The  pupil  is  not  directly  under  control  of  the  will. 
Its  movements  originate  (1)  by  reflex  stimulation,  or  (2) 
by  synkineses,  i.e.,  the  pupillary  movement  is  associated 
with  other  voluntary  or  reflex  movements.  There  are  two 
chief  reflexes  and  two  chief  sjmkineses,  giving  in  all  (1) 
the  light  reflex;  (2)  the  accommodation  synkinesis;  (3) 
the  sensory  reflex;  and  (4)  the  cerebral  or  psychic 
synkinesis. 

The  optic  ners^e  contains  fibres  from  all  parts  of  the 
retina.  The  pupillar)^  fibres  decussate  partially  in  the 
chiasm  and  pass  into  the  optic  tract.  Since  destruction 
of  the  lateral  geniculate  body  does  not  destroy  the  light 
reflex  (v.  Bechterew,  "^  Henschen  "5) ,  the  pupillary  paths 
evidently  do  not  enter  this  body. 

Flourens^^  believed  the   pupillary   constrictor   centra 

m 


106  SEMICIRCULAR   CANALS 

was  in  the  corpora  qiiadrigemina;  but  Knoll,  "^  who  was 
confirmed  by  v.  Bechterew  and  by  Ferrier  and  Turner,"^ 
showed  that  the  superior  coUiculi  might  be  removed  with- 
out abolition  of  the  light  reflex.  According  to  Bogroff  and 
Flechsig  "^  a  tract  passes  from  the  optic  tract  directly 
into  the  stratum  griseum  centrale.  v.  Bechterew"^  be- 
lieves the  pupillary  fibres  leave  the  optic  tract  at  the  level 
between  the  corpus  cinereum  and  the  root  fibres  of  the 
third  nerve,  near  the  entrance  of  the  optic  tract  into  the 
external  geniculate  body,  and  run  thence  to  the  posterior 
part  of  the  third  ventricle,  where  they  end  about  neurones 
that  send  axones  to  the  third  nucleus  of  the  same  side. 
V.  Bechterew  ^^o  also  believes  that  pupillary  fibres  pass  in 
the  superior  peduncle  between  the  third  nucleus  and  the 
cerebellum.  The  paths  are  crossed  and  convey  impulses 
in  both  directions. 

Darkschewitsch  ^21  believes  the  pupillary  fibres  leave 
the  optic  tract  near  the  external  geniculate  body  and  pass, 
through  the  thalamus  to  the  ganglion  habenulae,  being 
relayed  thence  through  the  posterior  commissure  to  the 
nucleus  bearing  his  name.  But  v.  Bechterew  and  others 
showed  that  this  nucleus  is  not  related  to  the  third  nerve. 

Bernheimer  ^22  thinks  the  pupillary  fibres  pass  directly 
to  the  third  nucleus.  Bach,^^^  however,  could  not  con- 
firm this  view.  It  is  still  a  question  as  to  what  the  defin- 
ite path  of  the  pupillary  fibres  is.  It  seems  most  likely 
(Parsons*^)  that  these  fibres  pass  by  the  superior  brachium 
into  the  superior  colliculi,  and  by  means  of  new  connec- 
tions the  jmths  i)ass  to  the  third  nucleus  of  the  same  and 
opposite  side.  The  difficulty  about  this  is  that  extirpa- 
tion of  the  colliculi  does  not  abolish  the  light  reflex.  Par- 
sons, however,  states  that  the  pupillary  fibres  end  in  the 
lateral  portion  of  the  colliculi  which  was  not  removed  in 
the  experiments  of  Ferrier  and  Turner."^ 

According  to  Sacki  and  Schmaus,^'^^Shaeffer,i25  Argyll- 
Robertson,  ^^e  Wolff,  127  Ruge^^s  and  others,  pupillary  con- 
striction is  caused  in  part  by  inhibition  of  dilatation. 
Parsons, ^'-^  Anderson  "^  and  others  maintain  that  pupillary 
constriction  is  solely  effected  by  the  constrictor  centre. 
The  grounds  for  such  a  view  are:  (1)  After  section  of  the 
third  nerve  variation  in  tin;  ilkimination  does  not  affect 
the  pupil;  (2)  paradoxical  pupil  dilatation  may  arise  and 


ANATOMY  107 

persist  for  one  minute  in  strong  sunlight;  (3)  the  irregu- 
larity of  the  pupils  consequent  on  sympathectomy  is  not 
diminished,  but  rather  increased,  by  bright  illumination 
of  the  eyes.  These  reasons  are  scarcely  sufficient  to  elimi- 
nate dilator  inhibition  in  the  light  reflex. 

It  is  generally  accepted  that  the  centre  for  pupil  con- 
striction is  located  in  the  third  nucleus.  Marina  ^29 
thinks  the  ciliary  ganglion  contains  the  centre  for  the 
light  reflex.  His  experiments,  however,  are  not  con- 
vincing. 

The  efferent  pupillo-constrictor  path  passes  via  the 
third  nerve  (branch  to  the  inferior  oblique)  to  the  ciliary 
ganglion  where,  after  interruption,  the  paths  are  continued 
in  the  short  ciliary  nerves  to  the  iris. 

Langley  and  Anderson,  ^^^  Apolant,  ^^  Langendorff  ^^^ 
and  others  have  shown  that  the  third  nerve  fibres  enter- 
ing the  ciliary  ganglion  end  about  the  cells  of  the  latter 
as  preganglionic  fibres,  the  paths  being  continued  through 
postganglionic  fibres  into  the  short  ciliary  nerves  and  so 
to  the  iris.  The  exact  nature  of  the  cells  in  the  ciliary- 
ganglion  has  been  a  matter  of  much  investigation  and 
controversy.  Langley  and  Anderson^^^  and  Langendorff  ^^2 
have  shown  that  the  ganglion  contains  no  spinal  ganglion 
elements.  The  more  recent  work  of  Anderson  ^^^  showed 
that  after  removal  of  the  ciliary  ganglion  there  was  no 
degeneration  of  medullary  fibres  in  the  HI,  IV,  V,  or  VI 
nerves.  Jegerow  ^^^  found  that  after  section  of  the  third 
nerve  removal  of  the  ciliary  ganglion  increased  the  dilata- 
tion of  the  pupil.  And  since  excision  of  the  superior 
cervical  ganglion  reduces  the  number  of  cells  in  the 
ciliary  ganglion  (Bumm^'*^),  and  eserine  does  not  con- 
trol the  pupil  so  efficiently  after  sjTiipathetic  ganglionec- 
tomy  (Levinsohn  ^^^) ,  we  may  conclude  that  some  con- 
strictor paths  find  their  way  to  the  ciliary  ganglion 
through  the  s}Tnpathetic.     (See  also  Onuf  and  Collins  ^o^. ) 

Anderson  ^^^  removed  the  ciliary  ganglion  in  kittens, 
and  after  a  few  days  found  that  by  partially  asphyxiating 
or  killing,  or  by  dividing  the  third  nerve,  the  dilated 
pupil  became  smaller  than  the  control.  This  phenome- 
non, known  as  paradoxical  pupil  contraction,  he  attribu- 
ted to  increased  excitability  of  the  paralyzed  muscle. 
The  phenomenon  is  not  of  as  frequent  occurrence  as  the 


108  SEMICIRCULAR  CANALS 

parallel  phenomenon  paradoxical  pupil  dilatation  occur- 
ring sometimes  after  removal  of  the  superior  cervical 
ganglion. 

The  pupillo-dilator  tract  begins  probably  in  the  mes- 
encephalon near  the  third  nucleus.  Passing  caudad  by 
unknown  paths  it  descends  in  the  lateral  tract  of  the  cord. 
In  the  cat,  dog  and  ape  the  paths  leave  the  cord  by  the 
ventral  roots  of  the  three  upper  thoracic  nerves,  enter  the 
rami  communicantes,  and  pass  to  the  first  thoracic  or  stel- 
late ganglion.  From  this  point  most  of  the  fibres  pass  by 
way  of  the  anterior  limb  of  the  annulus  of  Vieussens, 
some  fibres  also  passing  in  the  posterior  limb,  up  the 
neck  in  the  cervical  sympathetic  to  the  superior  cervical 
ganglion.  From  the  latter  the  tract  enters  the  skull  by 
the  cervico-Gasserian  strand,  and  runs  independently  of 
the  carotid  plexus  to  join  the  Gasserian  ganglion;  pass- 
ing thence  into  the  first  or  ophthalmic  division  of  the  fifth 
nerve,  following  the  nasal  branch,  the  tract  finally  leaves 
the  latter  to  enter  the  long  ciliary  nerves,  thus  avoiding 
entrance  into  the  ciliary  ganglion.  The  long  ciliary  nerves 
enter  the  eye  on  each  side  of  the  optic  nerve,  and  pass 
forward  between  the  chorioid  and  sclerotic,  through  the 
ciliary  body,  to  be  distributed  to  the  iris.  In  the  course 
of  this  path  lie  the  superior-cilio-spinal  centre  which  is 
a  hypothetical  centre  in  the  medulla  near  the  XII  nucleus, 
and  the  inferior  cilio-spinal  centre  of  Budge,  ^^^  which  lies 
in  the  cord  between  the  sixth  cervical  and  fourth  thoracic 
vertebrae.  Schiff,^"  however,  showed  that  the  inferior 
cilio-spinal  was  not  an  independent  automatic  centre. 
It  may  be  noted  that  the  above  includes  only  efferent 
paths,  or  at  least,  it  does  not  include  afferent  paths  lead- 
ing to  the  mesencephalic  centre,  although  it  is  probable 
that  the  exclusion  of  light  acts  as  a  positive  stimulus  to 
the  dilator  mechanism  (Howell  ^^) . 

The  existence  of  a  pupillo-dilator  muscle  has  been 
much  studied  and  discussed.  Maunoir  ^^^  first  propounded 
it,  but  no  uniformity  of  opinion  so  far  prevails.  The 
difficulty  seems  to  attach  itself  chiefly  to  the  histological 
differentiation  between  the  radial  fibres  and  the  blood- 
vessels of  the  iris,  and  to  the  interpretation  of  the  nature 
of  the  cells  in  the  posterior  layer  of  the  iris  (Parsons  ^^). 
The  present  state  of  the  question  seerns  to  be  that  ttie  aii- 


ANATOMY  109 

terior  layer  of  the  retinal  pigmented  epithelium  acts  as  a 
dilator  muscle  (Grunert  ^'^^) .  The  cells  on  bleaching  look 
like  plain  muscle  fibres  and  stain  in  the  same  manner. 
Whatever  be  the  state  of  the  question  from  the  anatomi- 
cal point  of  view,  Langley  and  Anderson  ^^^  have  demon- 
strated conclusively  the  existence  of  a  dilator  of  the  pupil. 

Homolateral  pupillary  constriction  following  section 
of  the  cervical  sympathetic  was  first  pointed  out  by  Par- 
four  du  Petit.  ^^°  Removal  of  the  superior  cervical  gan- 
glion was  found  to  cause  wider  pupillary  dilatation  than 
simple  section  of  the  nerve  trunk  (Frangois-Franck  ^^^ 
and  others) .  The  general  effect  of  sjmipathectomy  or  of 
ganglionectomy  are :  miosis,  narrowing  of  the  palpebral 
aperture,  projection  of  the  nictitating  membrane,  retrac- 
tion of  the  globe  (Langendorff  ^^^) ,  hyperaemia  of  the  con- 
junctiva (Heese^^^),  temporarily  increased  secretion  of 
tears  due  to  hyperaemia  (Levisohn^^^),  diminution  of 
intra-ocular  tension  (Adamiik,^^^  Selenkowski  and  Rosen- 
berg^s^),  degeneration  of  the  retinal  ganglion  cells  and 
optic  nerve  (Lodato^^^^^  vascular  injection  of  the  eye- 
ground  upon  the  side  of  operation  (Sinitzen  ^^^)  and 
perhaps  trophic  disturbances. 

Galvanic  or  faradic  stimulation  of  the  cervical  sympa- 
thetic causes :  homolateral  pupillary  dilatation  with  pu- 
pillary constriction  on  the  opposite  side  (Schenk  and 
Fuss  ^^^) ;  change  in  the  color  of  the  iris  because  of  dis- 
placement of  its  fibres;  retraction  of  the  nictitating 
membrane  and  widening  of  the  palpebral  fissure  with 
protrusion  (retraction  in  the  rabbit,  Heese)  of  the  eyeball 
(Katschew^^^) ;  constriction  of  the  vessels  of  the  conjunc- 
tiva, iris  and  retina  (Heese  ^^^) ;  increased  intraocular 
tension  (Adamtik^^^)  and  diminished  lachr}mial  secre- 
tion (Wolferz  and  Demtschenko  ^9°)  the  last  effect  being 
the  result  of  vascular  changes  (Campos  "^  and  Levisohn^^^) . 
Lodato  found  that  slow  irritation  of  the  sympathetic, 
e.  g. ,  by  implantation  of  a  foreign  body,  causes  dilatation 
of  the  homo-lateral  pupil.  This  pupil  reacts  slightly  to 
light,  but  more  so  to  light  flashed  in  the  opposite  pupil, 
Lodato  attributed  the  phenomenon  to  retinal  anaemia, 
Schenk  and  Fuss^^^  confirmed  Dogiel's  observation  that 
stimulation  of  the  cervical  sympathetic  tended  to  cause 
Qonstriction  of  the  opposite  pupil,  but  showed  that  it 


110  SEMICIRCULAR   CANALS 

was  due  to  the  consensual  reflex.  As  the  latter  is  absent 
in  rabbits  the  authors  did  not  observe  the  phenomenon  in 
these  animals. 

Under  certain  circumstances  after  sympathetic  gan- 
glionectomy,  e.g.,  excitement,  dyspnoea,  anaesthesia,  or 
death,  the  pupil  may  dilate  instead  of  contracting  (Lan- 
gendorff,^s3  Anderson, ^^^  Lewandowski,^^^  and  others). 
This  phenomenon  is  known  as  paradoxical  pupillo-dila- 
tation.  The  cause  is  attributed  by  Anderson  ^^^  to  in- 
creased automatic  excitability  of  the  dilator  contractile 
tissues,  this  latter  condition  being  in  turn  attributed  by 
Langendorff  ^^^  to  degeneration  of  the  nerve  elements. 

The  accommodation  synkinesis  is  considered  to  be 
merely  a  constrictor  effect  accompanying  accommodation, 
or  rather  convergence.  The  phenomenon  is  not  consid- 
ered to  be  a  true  reflex.  Weber,  ^^^  however,  proved  by 
means  of  prisms  that  constriction  occurred  in  convergence 
without  accommodation  and  not  vice  versa^  and  it  is  well 
known  clinically  that  the  accommodation  phenomena  are 
absent  in  paralysis  of  the  third  nerve.  Moreover,  even 
when  the  pupil  is  very  small,  it  can  be  made  to  contract 
by  convergence,  whereas  in  fixation  for  distance  in  these 
instances  the  degree  of  dilatation  corresponds  exactly 
with  that  of  the  previous  constriction.  These  considera- 
tions coupled  with  the  presence  of  Golgi-Mazzini  end- 
organs  in  the  tendons  of  the  ocular  muscles  tend  to  show 
that  accommodation  constriction  resembles  a  true  reflex 
mediated  through  varying  tension  in  the  different  ocular 
muscles.  Clinical  observation  shows  that  with  one  eye 
closed  and  held  firmly  so  as  to  prevent  convergence, 
efforts  at  accommodation  cause  little,  if  any,  constriction. 

The  dilatation  observed  by  Hensen  and  Volkers  ^^  on 
stimulation  of  the  VI  nucleus  can  be  accounted  for  by 
inhibition  of  the  internal  rectus,  coupled  perhaps  with 
active  dilatation,  as  Sherrington  212  has  shown  by  cortical 
stimulation  that  reciprocal  innervati(m  obtains  between 
these  muscles.  Langley  ^^3  ^^s  shown  that  the  superior 
cervical  ganglion  sends  post-ganglionic  fibres  to  the  III 
and  VI  nerves.  The  function  of  these  fibres  is  not  known. 
Thoy  were  formerly  supposed  to  be  vaso-motor  for  the 
ocular  muscles,  but  subsequent  experiments  have  dis- 
proved this. 


ANATOMY  111 

• 

The  sensory  pupil  reflex  consists  in  dilatation  induced 
by  tactile,  pathic  and  other  sensory  stimuli.  Upon  the 
application  of  any  of  the  stimuli  named,  there  is  at  first 
a  rapid,  short-lived,  primary  dilatation  due  to  reflex 
augmentation  of  the  dilator  tone.  This  is  followed  by  a 
second  dilatation  rapid  in  onset  but  slow  in  disappearing, 
and  due  to  inhibition  of  constrictor  tone  (Anderson  ^^^) . 

The  sensory  reflex  was  first  obtained  on  stimulation  of 
the  posterior  fasciculi  of  the  cord  by  Chauveau,  who  found 
that  the  effect  was  abolished  by  section  of  the  cord  above 
Budge's  inferior  cilio-spinal  centre.  Later  Bernard  ^^^ 
showed  that  stimulation  of  any  sensory  nerve  evoked  the 
reflex,  and  Balogh  ^^^  that  it  could  be  evoked  after  removal 
of  the  superior  cervical  ganglion,  v.  Bechterew  main- 
tained that  the  sensory  reflex  was  entirely  due  to  inliibi- 
tion,  but  Anderson  ^^2  got  well-marked  dilatation  from 
stimulation  of  the  sciatic  nerve  after  division  of  the 
pupillo-constrictor  path.  This  dilatation,  which  was 
accompanied  by  the  other  phenomena  associated  with 
stimulation  of  the  cervical  sjmipathetic,  was  absent  if  the 
cervical  sympathetic  as  well  as  the  third  nerv^e  had  been 
previously  cut. 

The  cerebral  synkinesis  (psycho-kinesis,  Parsons)  is 
the  name  given  to  alterations  of  the  pupil  induced  by 
psychic  stimuli,  e.g.,  fear,  the  thought  of  a  bright  light, 
etc.  It  is  also  to  a  great  extent  an  association  of  ocular 
movements  which  themselves  may  be  the  result  of  sen- 
sory impulses  (Parsons  ^^).  Haab^^  first  described  the 
phenomenon. 

Pupil  dilatation  and  constriction  have  been  observed 
by  Hitzig,2oi  Ferrier,^  Braunstein,  202  and  many  other 
physiologists  upon  stimulation  of  various  regions  of  the 
brain.  It  was  generally  found  that  dilatation  was  more 
easily  produced  than  constriction,  but  no  strict  localiza- 
tion could  be  made  out.  Most  observers  considered  the 
effects  as  complications  rather  than  direct  results  from 
local  stimulation  of  the  cortex.  The  dilatation  is  usually 
accompanied  by  the  other  known  effects  of  stimulation  of 
the  cervical  sympathetic.  Section  of  this  latter  abolishes 
all  these  effects  but  the  pupillary  dilatation,  and  this  it 
diminishes.  With  both  sympathetics  intact,  full  dilata- 
tion of  the  pupils  occurs  in  epileptoid  convulsions  result- 


11^  SEMICIRCULAR  CANALS 

ing  from  prolonged  or  frequently  repeated  excitation  of 
cortical  motor  areas  (Parsons  ^^^) . 

In  Parsons'  experiments  upon  cats  tlie  following  areas 
of  the  brain  on  stimulation  caused  pupil  dilatation  after 
destruction  of  all  possible  sympathetic  paths :  (1)  A  con- 
siderable area  about  the  crucial  sulcus;  (2)  the  mesial 
surface  of  the  hemisphere  in  the  occipital  region  near  the 
crucial  sulcus ;  (3)  the  anterior  part  of  third  or  median 
convolution.  Ferrier^  got  constriction  and  divergence 
from  this  latter  area  in  the  dog.  In  exceptional  cases 
transitory  constriction  preceded  dilatation. 

In  the  occipital  region,  in  the  posterior  part  of  the 
third  or  median  convolutions,  Ferrier  got  constriction, 
but  Parsons  could  not  confirm  the  observation  upon  the 
cat  whilst  Frangois-Franck  got  temporary  constriction 
followed  by  dilatation.  Parsons  got,  upon  the  dog,  re- 
sults similar  to  those  obtained  upon  the  cat,  and  con- 
cluded that  there  probably  exist  in  the  frontal  and  occipi- 
tal areas  foci  for  constriction,  but  that  these  are  masked 
by  the  dilator  effects,  which  are  more  easily  produced. 

Section  of  the  third  nerve  after  previous  division  of 
the  cervical  sympathetic,  left  the  puj)il  immobile  and 
three-quarters  dilated.  Stimulation  of  the  cortex  was 
then  without  effect. 

Section  of  the  corpus  callosum  was  without  effect 
upon  dilatation  from  cortical  stimulation.  Hence  the 
bilateral  effect  was  not  due  to  stimulation  acting  through 
the  opposite  cortical  areas,  but  to  its  effect  upon  the 
lower  centres. 

Stimulation  of  the  anterior  and  posterior  part  of  the 
corona  radiata  and  internal  capsule,  i.e.,  fibres  from  the 
frontal  and  occipital  areas,  caused  bilateral  dilatation  of 
the  pupils.  In  one  case  there  was  constriction  and  con- 
vergence from  stimulation  of  the  posterior  part  of  the 
internal  capsule. 

Sherrington, 2^^  after  vagus  and  spinal  transection 
which  cut  off  impulses  from  above  and  those  from  below 
via  the  cervical  sympathetic,  found  the  pupils  dilated  as 
if  in  anger.  This  indicates  that  in  pupil  dilatation  from 
stimulation  of  the  cerebral  cortex  after  section  of  the 
sympathetic,  the  mechanism  consists  in  inhibition  of  the 
constrictor  mechanism.     Another  theory  bases  the  mech- 


ANATOMY  llg 

anism  of  this  dilatation  upon  vascular  changes  in  the 
iris.  But  all  the  vaso-motors  for  the  iris  run  in  the  cer- 
vical sympathetic,  and  Langley  and  Anderson  ^'^  have 
shown  that  vaso-motor  changes  whilst  they  may  affect  the 
pupil,  do  not  do  so  to  such  an  extent  as  to  make  them 
independent  factors  to  any  important  degree. 

It  may  be  remarked  that  Onuf  and  Collins, ^^^  Frangois- 
Franck  and  others  believe  that  all  the  mydriatic  paths 
are  not  confined  to  the  cervical  sympathetic. 

Ferrier  ^  obtained  pupil  constriction  from  the  anterior 
and  posterior  limbs  of  the  angular  gyrus  in  the  monkey, 
and  from  the  third  external  or  coronal  convolution  in 
dogs.  Parsons  ^"^  failed  to  confirm  these  observations, 
but  Frangois-Franck  and  Pitres  ^^  saw  transitory  con- 
striction from  stimulation  of  the  former  area. 

In  pigeons  Ferrier  observed  intense  pupil  constriction 
on  irritation  of  the  middle  of  the  convexity  of  the  hemi- 
sphere. Schafer  ^^  got  marked  constriction  from  stimula- 
tion of  the  quadrate  lobule,  whilst  in  monkeys  Ferrier 
also  got  fairly  constant  homolateral  pupil  constriction 
from  irritation  of  certain  areas  of  the  cerebellum. 

Parsons  concluded  that  the  phenomena  of  pupil  dilata- 
tion and  contraction  from  irritation  of  the  cerebral  cortex 
are  mere  associations,  since  they  do  not  occur  in  the 
absence  of  ocular  movements.  The  movements  obtained 
from  the  sensory  areas,  e.g.,  from  the  visual  centres  in 
the  occipital  cortex  are  due  to  ill-defined  visual  sensations 
leading  to  appropriate  movement  of  the  head  and  eyes. 
The  mere  fact  of  association  with  ocular  movements  tends 
to  show  that  movements  of  the  iris,  like  other  ocular 
movements,  have  higher  representation  than  that  of  merely 
spinal  or  analogous  motor  nuclei. 


CHAPTER  VIII 

FURTHER   ANATOMICAL   AND   PHYSIOLOGICAL 
CONSIDERATIONS 

Before  approaching  the  study  of  the  semicircular 
canals  it  is  proper  to  note  further  a  few  fundamental  facts 
concerning  the  anatomical  and  physiological  relations  of 
the  cerebellum  with  other  structures. 

The  following  may  be  accepted : 

1.  The  cerebellar  hemisphere  is  in  close  anatomical 
and  physiological  relation  with  the  cerebral  hemisphere 
and  inferior  olivary  body  of  the  opposite  side.  In  Fer- 
rier's^^  case  marked  atrophy  of  the  cerebellar  hemisphere 
was  found  in  a  criminal  lunatic  with  atrophy  of  the 
contra-lateral  cerebral  hemisphere.  Starr  has  a  similar 
specimen  from  a  weak-minded  child  who  had  always  been 
irregular  in  gait  and  balanced  with  difficulty.  The  child 
died  when  three  years  old  from  measles.  There  was 
found  almost  complete  absence  of  the  cerebellum  on  one 
side  with  marked  atrophy  of  the  fibres  of  the  pons  and 
inferior  olive  of  the  opposite  side.  Gudden  ^^  found  on 
extirpation  of  one-half  of  the  cerebellum  ensuing  atrophy 
of  the  opposite  olive.  Many  instances  of  cerebellar  defect 
have  been  discovered  at  autopsy  in  individuals  who,  in 
life,  were  considered  to  be  fairly  normal. 

2.  Each  half  of  the  cerebellum  controls  for  the  most 
part  the  movements  of  muscles  on  the  same  side  of  the 
body. 

Ferrier's^  experiments  showed  that  stimulation  of  one 
side  of  the  cerebellum  was  always  accompanied  by  move- 
ment of  the  muscles  on  the  side  stimulated,  and  by 
certain  characteristic  movements  of  the  eyes.  This 
proposition  seems  a  corollary  of  the  first.  Each  cerebral 
hemisphere  controls  the  muscles  of  the  opposite  side  of 
the  body,  and  at  the  same  time  is  in  intimate  relation 

114 


ANATOMY  115 

with  the  cerebellar  hemisphere  of  the  opposite  side. 
Further  developraents  will  show  that  this  relationship  is 
the  one  best  calculated  to  aid  the  function  of  equilibra- 
tion. 

3.  The  cerebellum  acts  wholly  in  a  reflex  manner,  i.e., 
beneath  the  level  of  consciousness.  This  is  generally  ad- 
jnitted  by  investigators.  Hence  afferent  and  efferent 
paths  are  required.  The  afferent  paths  place  the  cerebel- 
lum in  relation  with  the  specialized  sensory  organs  of 
equilibration,  the  chief  of  which  are  the  semicircular 
canals,  the  eyes,  and  those  structures  in  which  kinsesthetic 
impulses  originate,  viz.,  the  skin,  muscles,  tendons, 
articular  surfaces,  etc.  The  cerebrum,  however,  besides 
being  capable  of  exerting  control  over  the  muscles  in- 
volved in  equilibration  and  in  ocular  movements  has,  in 
man,  to  be  reckoned  as  an  important  source  of  afferent 
cerebellar  impressions  in  acts  of  equilibration.  The 
phenomena  of  conjugate  deviation  observed  by  Schafer 
and  Mott,^^  and  by  Kisien-Russell  ^^  on  stimulation  and 
ablation  of  the  ocular  centres  in  the  frontal  lobe  and  the 
similar  phenomena  that  sometimes  accompany  cerebral 
hemorrhage,  closely  resemble  those  observed  on  stimula- 
tion (Ferrier^),  or  ablation  (Luciani^^),  of  parts  of  the 
cerebellum  or  section  of  the  cerebellar  peduncles,  or  of 
the  auditory  nerve.  These  phenomena  are  best  explained 
by  assuming  the  existence  of  cerebral  and  cerebellar  tonus 
balanced  mechanisms,  working  in  harmony  and  in  a  reflex 
manner,  the  cerebral  motor  mechanisms  of  one  side  acting 
in  harmony  with  the  corresponding  mechanisms  of  the 
opposite  half  of  the  cerebellum. 

In  addition  to  the  direct  tonus  influence  which  the 
cerebral  centres  exert  upon  the  ocular  and  other  muscles 
itVould  seem  that  the  cerebrum  is  an  important  source  of 
afferent  cerebellar  impressions  whereby  it  influences  the 
actions  of  the  cerebellar  mechanisms  upon  the  ocular  and 
other  muscles. 

In  other  words,  afferent  cerebellar  paths  conduct  im- 
pulses from  the  various  parts  of  the  cerebral  cortex  to  the 
cerebellum.  Such  cerebro-cerebellar  paths  are  somewhat 
analogous  to  those  from  the  semicircular  canals,  and 
from  the  peripheral  kinsesthetic  end  organs.  The  im- 
pulses conveyed  by  them  act  probably  after  the  manner  of 


116  SEMICIRCULAR   CANALS 

those  conveyed  by  the  vestibular  or  kinaesthetic  paths  in 
influencing  cerebellar  action. 

In  a  large  cerebral  hemorrhage  confined  to  one  hemi- 
sphere not  only  is  the  independent  action  of  the  cerebral 
centres  for  the  head  and  eyes  suspended,  but  the  cerebral 
influence  exerted  through  the  cerebro-cerebellar  paths  is 
in  abeyance.  The  consequent  conjugate  deviation  results 
from  removal  of  the  direct  cerebral  tonus,  as  well  as  of 
the  associated,  indirect,  cerebro-cerebellar  tonus  on  one 
side  of  the  body,  leaving  the  opposing  mechanisms  of 
the  opposite  side  in  free  and  unopposed  control.  The 
phenomena  following  section  of  the  superior  and  middle 
peduncles  of  the  cerebellum  seem  to  afford  grounds  for 
this  assumption.  It  may,  therefore,  be  concluded  that 
the  cerebrum  besides  exerting  tonic  influence  directly  on 
muscle,  can  also  affect  muscle  tone  indirectly  through  the 
medium  of  the  cerebellum.  The  anatomical  relations 
strongly  corroborate  this  view.  The  fact  that  removal  of 
the  cerebral  hemispheres  of  the  frog  does  not  disturb  the 
functions  of  equilibration  to  any  extent,  does  not  contra- 
vene this  view  because  the  hemispheres  are  relatively 
unimportant  structures  in  the  frog,  as  compared  with 
man,  and  bilateral  lesions  tend  to  counterbalance  each 
other,  leaving  the  remaining  elements  of  the  balanced 
mechanisms  to  control  acts  of  equilibration.  The  turn- 
ing of  the  eyes  to  the  side  of  the  lesion  in  cerebral  apo- 
plexy accords  with  Ferrier's^  experiments,  in  which 
stimulation  of  the  cerebellum  on  one  side  was  invariably 
followed  by  turning  of  the  eyes  toward  that  side.  These 
matters  shall  receive  further  discussion  in  a  later  chapter. 

The  cerebellum  by  means  of  its  afferent  and  efferent 
peripheral  relations  constantly  holds  the  muscles  involved 
in  equilibration  in  a  state  of  tone  ever  ready  to  respond 
to  impulses  originating  from  change  of  j^osition  (Ewald) 
or  other  stimulus.  This  tonic  influence  is  bilateral,  each 
half  of  the  cerebellum  controlling  in  the  main  the  muscles 
on  the  homolateral  side.  Thus  delicate  cerebellar  mech- 
anisms are  constantly  active  in  the  reflex  maintenance  of 
equilibrium.  Sometimes  these  mechanisms  work  unaided 
and  at  other  times  in  conjunction  with  the  higher  volun- 
tary motor  centres.  Serious  interference  with  the  affer- 
ent, efferent,  or   central   elements  of   the   reflex  arcs  of 


ANATOMY  117 

these  mechanisms  results  in  disturbances  of  equilibrium, 
incoordinated  action  of  the  muscles  of  dynamic  equilib- 
rium and  other  phenomena.  Such  disturbances,  if  of 
mild  degree,  may  be  corrected  by  voluntary  effort,  but 
this  latter  is  always  awkward,  very  exhausting,  and 
requires  the  constant  attention  of  the  individual,  which  is 
the  opposite  of  what  occurs  in  normal  equilibration. 
Compare  the  results  observed  by  Weir-Mitchell^^  in 
pigeons  after  injury  to  the  cerebellum 

4.  The  peripheral  end  organs  of  the  vestibule  and 
semicircular  canals  are  mainly  in  crossed  relation  with 
the  cerebellum  through  the  vestibular  nerve,  v.  Bech- 
terew  maintains  the  contradictory  of  this  proposition. 
The  succeeding  chapters,  as  well  as  careful  study  of  the 
fibre-paths,  will  reveal  this  crossed  relationship.  Ferrier^ 
has  shown  that  the  cochlear  apparatus  is  in  relation 
mainly  with  the  temporo-sphenoidal  lobe  of  the  opposite 
side.  He  found  on  stimulation  of  the  auditory  area  in 
monkeys,  cats,  dogs  and  jackals,  pricking  of  the  oppo- 
site ear,  wide  opening  of  the  eyes,  dilatation  of  the 
pupils,  and  turning  of  the  head  and  eye  to  the  opposite 
side,  thus  indicating  the  direction  of  the  source  of  the 
imagined  sound.  These  experiments  were  repeated  many 
times,  and  on  both  sides  of  the  brain. 

Before  proceeding  further,  it  is  proper  to  call  attention 
to  such  terms  as  "rolling  on  the  long  axis  to  the  side  of 
operation"  in  animals,  and  to  contrast  it  with  "revolving 
to  the  right  or  left,  or  to  the  side  of  the  lesion,  on  the 
long  axis"  in  man.  Owing  to  the  difference  in  posture 
normally  assumed  by  man  and  the  quadrupeds,  these 
expressions  have  altogether  a  different  meaning.  In  the 
case  of  a  dog  ' '  rolling  on  the  long  axis  toward  the  side  of 
operation, ' '  means  that  the  direction  of  the  motion  would 
be  represented  by  a  bent  arrow  passing  transversely  over 
the'dorsal  aspect  of  the  animal,  whilst  in  the  case  of  man 
the  direction  would  be  indicated  by  a  bent  arrow  passing 
transversely  across  the  ventral  aspect  of  the  body.  The 
rotations  in  the  two  instances,  though  in  the  same  direc- 
tion, would  be,  according  to  current  forms  of  expression, 
absolutely  in  opposite  directions.  A  similar  difficulty  is 
encountered  in  describing  movements  of  the  eyeballs  oc- 
curring in  nystagmus  and  ocular  deviations.     Thus,  it  is 


118  '     SEMICIRCULAR   CANALS 

said,  that  the  eyeballs  rotate  inward  or  outward,  or  from 
left  to  right  on  the  horizontal  antero-posterior  axis. 
Such  statements  afford  opportunity  for  misinterpretation. 
Thus  if  the  upper  part  of  the  visible  portion  of  the  eye- 
balls be  held  in  mind  as  the  point  of  observation,  the 
direction  will  be  indicated  by  an  arrow  pointing  one  way, 
whilst  if  the  lower  portion  of  the  eyeball  be  taken  as  the 
point  of  observation,  the  direction  will  be  indicated  by 
an  arrow  pointing  in  the  opposite  direction.  Hence  it 
seems  better  to  drop  the  terms  rotating  inward  and  out- 
ward, and  substitute  for  them  rotation  in  the  direction  of 
the  hands  of  a  watch  or  the  reverse,  the  watch  in  every 
instance  being  considered  as  held  facing  the  observer, 
and  in  a  plane  parallel  to  the  vertical  transverse  mesial 
(coronal)  plane  of  the  subject's  body.  Similarly  in  rota- 
tions with  the  subject  in  the  recumbent  posture  the  watch 
is  considered  as  placed  on  the  subject's  breast  with  the 
dial  looking  toward,  the  observer,  and  parallel  to  the 
coronal  plane  of  the  subject's  body.  The  direction  of 
certain  forms  of  rotation  can  then  be  designated  as  with 
or  against  the  hands  of  the  watch,  whilst  the  nystagmus, 
ocular  deviations  and  subjective  sensations  of  movement 
may  be  recorded  in  similar  terms. 

The  simple  reflex  arc  comprises,  according  to  Sher- 
rington, (1)  a  peripheral  receptive  portion  (receptor), 
(2)  a  peripheral  motor  portion  (effector) ,  and  (3)  a  con- 
ducting part  which  consists  of  the  afferent  and  efferent 
neurones.  "At  the  commencement  of  every  reflex  arc  the 
receptive  neurone  is  the  sole  avenue  for  impulses  generated 
at  its  receptive  point.  The  path  is  therefore  exclusive, 
and  other  receptive  points  cannot  employ  it.  A  single 
receptive  point  may  play  reflexly  on  a  number  of  differ- 
ent effector  organs,  e.g.,  on  many  muscles  and  glands  in 
different  regions,  yet  all  its  reflex  arcs  spring  from  one 
single  shank,  i.e.,  from  one  afferent  neurone  which  con- 
ducts from  the  recex:)tive  point  at  the  periphery  into  the 
central  nervous  organ.  At  the  end  of  every  reflex  arc  is 
the  motor  neurone,  the  last  conductive  link  to  an  effector 
organ.  This  receives  impulses  from  many  receptive 
sources  in  various  regions  of  the  body.  It  is  the  sole  path 
by  which  all  impulses,  no  matter  whence  they  come,  reach 
the  muscle  fibres.     The  receptor  neurone  forms  a  private 


ANATOMY  119 

path  exclusively,  serving  impulses  of  one  source  only. 
The  effector  neurone  is  a  public  or  common  path  for 
impulses  arising  at  many  sources  of  reception.  A  receptive 
field,  e.g.,  an  area  of  skin  is  analyzable  into  receptive 
points.  An  effector  organ  stands  in  reflex  connection  not 
only  with  many  individual  receptive  points,  but  with 
many  receptive  fields.  Impulses  generated  in  manifold 
sense  organs  can  pour  their  influence  into  one  and  the 
same  muscle.  Therefore,  in  reflex  arcs  the  initial  neurone 
of  each  is  a  private  path,  exclusive  for  a  receptor  point  or 
group  of  points,  and  finally  the  arcs  embouch  into  a  path 
leading  to  an  effector  organ,  and  their  final  common  path 
is  common  to  all  receptive  points  wheresoever  they  may 
lie  in  the  body,  so  long  as  they  have  connection  with  the 
effector  organ  in  question. 

' '  But  arcs  converge  to  some  degree  before  finally  con- 
verging upon  the  motor  neurone.  Their  private  paths 
embouch  upon  internuncial  paths  common  in  various 
degree  to  groups  of  private  paths.  The  terminal  path  is 
the  final  common  path  to  distinguish  it  from  internuncial 
common  paths.  The  motor  nerve  to  muscle  is  a  collection 
of  (parts  of)  final  common  paths.  Internuncial  paths 
conduct  and  converge  to  final  paths  or  to  further  inter- 
nuncial paths.  In  the  scratch  reflex  the  long  descending 
proprio-spinal  neurone  is  connected  with  a  whole  group 
of  afferent  neurones — private  paths  from  the  scalptor  re- 
ceptors in  the  skin  field  of  the  scratch  reflex.  Again,  in 
the  retina  and  olfactory  bulb,  Cajal  and  others  have  shown 
that  the  conducting  fibres  of  whole  groups  of  receptors 
impinge  upon  individual  neurones  of  the  next  relay.  The 
thalamic  neurones  form  a  path  upon  which  the  dorsal  col- 
umns, fillet,  and  spino-cerebellar  peduncular  paths  con- 
verge. Therefore,  each  internuncial  path  is,  to  some 
extent,  a  common  path,  just  as  the  receptive  neurone  is 
common  to  a  small  number  of  receptors.  The  ultimate 
path,  therefore,  differs  from  the  internuncial  path  only 
in  that  it  exhibits  communism  in  the  highest  degree" 
(Sherrington) . 

Because  each  instance  of  convergence  of  two  or  more 
afferent  neurones  upon  a  third  which,  in  regard  to  them 
is  efferent,  affords,  as  shown,  an  opportunity  for  coalition 
or  interference  of  their  action,  each  structure  at  which  it 


120  SEMICIRCULAR   CANALS 

occurs  is  a  mechanism  for  co-ordination  (Sherrington^). 
In  simple  reflexes  using  only  one  muscle  it  may  be  ac- 
cepted that  the  motor  neurone  is  the  final  common  path. 
In  complex  co-ordinated  reflexes  involving  the  simulta- 
neous action  of  several  muscles,  e.g.,  the  reflex  acts  of 
equilibration,  mediated  by  cerebellar  neurones,  the  spinal 
motor  neurones  cannot  be  the  final  common  path  which 
in  this  instance  must  of  necessity  consist  of  efferent  cere- 
bellar neurones,  using,  however,  various  spinal  motor 
neurones  to  manifest  its  influence  upon  the  effector  organs 
brought  into  play. 

The  receptor  organs  are  divided  (Sherrington)  into 
three  groups,  as  follows: 

L  The  exteroceptive  field  endowed  with  numerous 
receptive  organs  adapted  to  mechanical  contact — cold, 
warmth,  light,  sound,  injury  (noxa) ;  in  fact,  eveiy  mode 
of  stimulation  whereby  the  environment  can  affect  the  ex- 
ternal surface  of  the  body. 

2.  The  proprio-receptive  field  with  specific  receptor 
organs  adapted  to  modes  of  stimulation  obtaining  in  the 
muscles,  tendons,  joints,  walls  of  the  blood-vessels,  etc. 

8.  The  interoceptive  field,  co-extensive  with  the  inter- 
nal surface  of  the  body  (alimentary  canal,  etc.),  and  fur- 
nished scantily  with  receptor  organs  as  compared  with  the 
exteroceptive  field,  though  these  are  peculiarly  adapted  to 
chemical  agencies. 

Receptors  that  respond  to  stimuli  originating  from  an 
object  at  a  distance  from  the  body  are  known  as  projicient 
or  distance  receptors,  e.g.,  those  of  vision,  hearing,  and 
smell.  Such  receptors  tend  to  have  a  large  cortical 
representation  and  to  control  the  skeletal  musculature  as 
a  whole. 

Receptors  that  respond  to  the  action  of  noxious  agents 
which  threaten  immediate  harm  to  the  skin  are  known  as 
nociceptors.  Furthermore,  the  reflex  which  these  receptors 
excite  is  prepotent,  protects  by  escape  or  defence,  is  im- 
perative and  is  accompanied  by  pain. 

There  is  no  such  thing  as  a  purely  simple  reflex,  be- 
cause the  nervous  system  is  never  at  rest,  and  no  part  of 
it  is  disconnected  from  the  rest.  Reflexes  are  more  easily 
elicited  from  the  skin  (receptor  organs)  than  from  the 
afferent  nerve  trunk,  and  ^ome  are  only  elicited  from  a 


ANATOMY  121 

particular  surface  by  particular  Btimuli.  One  reflex  may- 
combine  harmoniously  with  another,  so  that  their  reac- 
tions mutually  reinforce  each  other.  Such  reflexes  are 
allied  and  their  neural  arcs  are  called  allied  arcs.  On 
the  other  hand,  some  reflexes  are  incompatible  and 
antagonistic,  i.e.,  one  inhibits  the  other  or  a  whole  group 
of  others.  The  reflex  or  group  that  inhibits  its  oppo- 
nents is  called  prepotent  for  the  time  being.  Nocicep- 
tive reflexes  override  (inhibit)  all  others  and  are  there- 
fore prepotent.  The  type  reflex,  e.  g. ,  the  scratch  reflex, 
etc. ,  results  from  the  harmonious  relation  between  allied 
reflexes  and  allied  arcs.  In  a  type  reflex  the  whole  motor 
centre  potentially  belongs  to  all  and  each  of  the  groups  of 
receptive  organs  proper  to  the  reflex.  The  elements  of 
the  centre  of  the  type  reflex  are  combined  and  incapable 
of  isolated  excitation. 

In  the  decerberate  dog  a  reflex  that  is  accompanied  by 
certain  mimetic  movements  simulating  certain  affective 
states,  e.g.,  anger,  pain,  etc.,  is  called  a  pseudo-affective 
reflex.  Pain  is  the  psychic  adjunct  of  a  protective  reflex. 
The  reflex  is  always  purposive. 

A  receptive  field  frequently  contains  receptors  of  two 
different  species,  e.g.,  tangoceptive  and  nociceptive  which 
may  not  both  of  them  initiate  reflexes  belonging  to  the 
same  type,  i.e.,  related  between  themselves  as  allied 
reflexes.  On  simultaneous  stimulation  of  these  two 
kinds  of  receptors  the  nociceptive  suppresses  the  tango- 
ceptive reflex.     This  is  known  as  reflex  complication. 

"The  compounding  of  reflexes  is  a  main  problem  in 
co-ordination.  Hence  the  common  path  is  a  feature" 
(Sherrington  ^^) . 

"In  the  scratch  reflex  there  is  an  end  effect  of  posi- 
tive sign  followed  by  an  inhibitory  phase  which  is  an  end 
effect  of  negative  sign.  This  succession  in  the  reflex  is 
repeated  many  times,  the  stimulus  being  continued.  The 
scratch  reflex  is  therefore  of  double  sign,  i.e.,  it  develops 
first  an  excitatory  and  then  an  inhibitory  end  effect. 

"In  the  flexion  reflex  of  the  hind  limb  of  a  spinal  dog 
or  cat,  the  end  effect  is  expressed  by  two  groups  of  muscles 
whose  contractions  act  in  opposed  direction  at  the  same 
joints.  This  opposition  is  obviated  at  the  end  of  the 
reflex  by  the  end  effect  having  the  form  of  excitatory 


122  SEMICIRCULAR   CANALS 

state  as  regards  the  motor  nerve  to  the  flexor  muscles,  but 
suppression  or  withholding  of  excitatory  state  (central 
inhibition)  as  regards  the  motor  neurones  of  the  extensor. 
This  is  a  reflex  of  double  sign,  whilst  the  scratch  and 
eyelid  reflexes  are  of  successive  double  sign"  (Sher- 
rington ^) . 

Although  the  intimate  nature  of  inhibition  is  but 
little  understood  it  has  been  clearly  demonstrated  by 
Sherrington  ^^  that  inhibition  is  an  active  process  and  an 
essential  part  of  the  reflex.  By  means  of  inhibition  the 
motor  neurones  are  precluded  from  the  arc  of  one  reflex 
whilst  left  open  to  another.  In  any  type  reflex,  inhibi- 
tion of  certain  muscles  appears  as  the  negative  aspect  of 
positive  excitation  in  other  muscles.  This  phenomenon 
which  seems  to  be  an  essential  part  of  every  reflex  move- 
ment constitutes  what  is  known  as  reciprocal  innervation. 
The  seat  of  inhibition  seems  to  be,  not  in  the  afferent 
or  efferent  neurone,  but  in  an  internuncial  mechanism 
between  them,  viz.,  the  ultimate  synapse.  The  objection 
made  to  the  spinal  motor  neurone  as  constituting  the 
final  common  path  for  complex  co-ordinated  reflexes  o^ 
equilibrium  seems  to  indicate  that  in  these  and  similar 
reflexes  the  seat  of  inhibition  is  not  placed  at,  or  near  the 
commencement  of  the  spinal-motor  neurone,  but  higher 
up,  viz. ,  at  the  commencement  of  the  cerebellar  or  other 
neurone  which,  in  this  instance,  is  the  commencement  of 
the  final  common  path.  Tonic  reflexes  of  posture  are  the 
most  readily  inhibited. 

From  the  foregoing  it  is  apparent  that  the  most  inti- 
mate functional  relations  obtain  between  the  various  parts 
of  the  nervous  system.  In  the  preceding  chapters  an  at- 
tempt was  made  to  trace  anatomically  these  connections, 
the  study  of  which  may  help  toward  an  understanding 
of  the  physiological  relations,  though  it  must  be  under- 
stood that  the  tracts  traced  only  crudely  and  indefinitely 
represent  the  actual  paths  employed  in  the  various  activi- 
ties of  nervous  system.  Thus,  whilst  it  is  not  possible 
to  trace  the  minute  anatomical  connections  it  seems  that 
every  final  motor  neurone,  or,  at  least,  every  common 
path  is,  to  some  extent,  in  relation  with  the  receptive 
areas  of  all  parts  of  the  body  through  afferent  arcs  of 
greater  or  less  resistance. 


PART  II 

PHYSIOLOGY  OF  THE  SEMICIRCULAR 
CANALS 


CHAPTER  IX 

PHYSIOLOGY  OF   THE  SEMICIRCULAR  CANALS  FROM 
THE  STANDPOINT  OF  ANIMAL  EXPERIMENTATION 

So  much  investigation  has  been  devoted  to  the  study  of 
the  semicircular  canals  that  it  would  take  more  space  than 
present  circumstances  permit  to  give  even  a  cursory  review 
of  the  work  done.  As  early  as  1693  Bannister,  an  English- 
man whose  researches  were  perhaps  the  first  experimental 
effort  in  this  direction,  observed  the  role  of  balancers  in 
certain  kinds  of  files,  and  noted  disturbances  of  equilibrium 
after  their  removal.  Since  Bannister's  time  the  literature 
of  the  semicircular  canals  teems  with  names  familiar  to 
every  student  of  medicine.  Only  a  few  can  be  mentioned, 
such  as  Scarpa,  Darwin,  Jackson,  Flourens,  Goltz,  De  Cyon, 
Hogyes,  Hitzig,  Spamer,  Brown-Sequard,  Lucas,  v.  Bech- 
terew,  Vulpian,  Baginsky,  Breuer,  Mach,  Crum-Brown, 
Laborde,  Koenig,  Lee,  Sewall,  James,  Kreidl,  Loeb,  Biehl, 
Dreyfus,  Schwartze,  Wanner,  Ewald,  von  Stein,  Delage, 
Engelmann,  Koryani,  Steiner,  Bruck,  Barany,  Neumann 
and  hosts  of  others. 

Flourens  was  the  first  to  point  out  the  intimate  relation- 
ship between  the  semicircular  canals  and  the  function  of 
equilibration.  He  showed  that  injury  of  the  membranous 
canals  was  followed  by  disturbances  of  equilibrium — vary- 
ing with  the  seat  of  the  lesion.  De  Cyon,  Goltz  and  others 
confirmed  Flourens's  observations. 

Flourens  ^^  and  De  Cyon,^'''  experimenting  on  the  semi- 
circular canals  of  pigeons,  obtained  the  following  results: 

Division  of  the  horizontal  canal  on  one  side  caused  a 
series  of  oscillations  of  the  head  in  the  horizontal  plane  on 
a  vertical  axis.  These  cease  in  a  short  time,  but  on  section 
of  the  corresponding  canal  on  the  other  side  they  reappear 
with  greater  intensity.    The  bird  cannot  now  maintain  it^ 

125 


126  SEMICIRCULAR   CANALS 

equilibrmm,  but  falls  or  turns  on  a  vertical  axis  or  circles 
round  and  round.  After  eight  to  ten  days  the  bird  recovers 
and  seems  normal  but  for  a  certain  awkwardness  seen  espe- 
cially in  flight. 

Division  of  the  posterior  vertical  canals  causes  similar 
but  more  violent  disturbances  of  equilibrium.  The  move- 
ments of  the  head  are  in  a  vertical  plane  on  a  horizontal 
axis.  The  pigeon  somersaults  head  over  heels.  The  dis- 
turbances subside  in  fourteen  days,  but  a  certain  brusquerie 
of  movement  remains,  with  an  almost  complete  inability 
to  fly. 

Division  of  the  superior  vertical  canals  causes  move- 
ments of  the  head  from  behind  forward  and  from  right  to 
left,  or  vice  versa,  with  profound  disturbances  of  equi- 
librium. The  bird  constantly  tends  to  somersault  heels  over 
head.  The  plane  of  the  movements  of  the  head  is  diagonally 
around  a  horizontal  axis.  The  movements  on  section  of 
the  canals  seem  therefore  to  take  place  in  the  plane  of  the 
canals  operated  on. 

In  rabbits,  section  of  the  canals  gave  results  similar  to 
those  obtained  in  pigeons,  but  more  enduring  and  the  oscilla- 
tions affected  the  eyeballs  more  than  the  head  and  trunk 
(De  Cyon^"^).  Section  of  one  horizontal  canal  caused  ten- 
dency to  movements  of  manege  (circus  movements).  Sec- 
tion of  one  vertical  canal  caused  the  animal  to  turn  on  the 
longitudinal  axis.  There  was  deviation  of  the  eyeballs 
and  nystagmus,  the  plane  of  the  oscillations  varying  with 
the  canal  injured,  but  the  oscillations  of  the  eyeballs  were 
more  or  less  independent  of  the  movements  of  the  head. 

In  frogs,  section  of  the  horizontal  canals  caused  the  head 
to  turn  on  the  long  axis  of  the  body,  the  animal  falling  to 
one  side  or  leaping.  Section  of  the  posterior  vertical  canals 
caused  the  animal  to  fall  on  its  back.  Section  of  the  other 
vertical  canals  caused  complete  somersaults  and  the  utmost 
disorder  of  movement. 

On  section  of  the  superior  vertical  canals  the  frog  swims 
in  an  upright  position,  pivoting  round  and  round.  Re- 
covery may  follow  destruction  of  all  the  canals  on  one  side. 
At  first  there  is  a  tendency  to  fall  to  the  injured  side,  and 
the  leg  of  this  side  gives  way  as  if  broken.  In  many  animals 
the  head  assumes  an  unnatural  position,  e.g.,  in  pigeons  the 


PHYSIOLOGY  127 

occiput  going  to  the  side  of  injury  and  the  beak  to  the 
opposite  side. 

After  destruction  of  the  canals  on  both  sides  equilibra- 
tion is  extremely  affected.  Pigeons'  after  a  time  learn  to 
walk,  but  the  disturbances  of  equilibration  recur  if  a  hood 
be  thrown  over  the  eyes.  After  some  months  the  birds  begin 
to  look  normal,  but  they  cannot  fly,  and  when  suddenly 
startled  their  confusion  of  movement  returns  and  they 
tumble  about  helplessly.  Animals  with  their  semicircular 
canals  destroyed  can  hear  (Flourens),  while  those  in  which 
the  cochlea  alone  has  been  destroyed  cannot  hear  but  can 
equilibrate.  This  accords  with  what  is  now  kno^vn  and 
accepted,  viz.,  the  complete  anatomical  and  physiological 
distinction  between  the  vestibular  and  auditory  fibres  and 
nuclei  of  reception  of  the  eighth  nerve. 

Section  of  the  auditory  nerve  in  frogs  gave  results  simi- 
lar to  those  obtained  on  section  of  the  semicircular  canals 
(Goltz^^).  Similar  effects  were  observed  in  dogs  by  v. 
Bechterew  ^^  on  section  of  the  eighth  nerve,  and  in  sheep 
and  horses  by  Biehl.'^  The  animals  rolled  round  toward  the 
side  of  operation  and  showed  a  skew  deviation  of  the  eyes, 
that  on  the  side  of  operation  looking  downward  and  out- 
ward, whilst  that  on  the  other  side  looked  upward  and  in- 
ward. The  oscillations  of  the  eyes  were  in  the  direction 
opposite  to  that  of  the  deviation.  Polling  movements  were 
most  marked  in  the  first  few  days,  being  almost  incessant. 
When  not  rolling  on  itsaxis  (longitudinal)  the  animal  lies 
on  the  side  of  section  with  this  side  of  the  head  downward. 
The  legs  on  the  side  of  section  are  doubled  up  close  to  the 
trunk,  but  flaccid,  whilst  those  of  the  opposite  side  are 
rigidly  extended  outward.  If  the  animal  is  placed  in  any 
other  position  than  on  its  side,  all  the  stiffness  of  the  limbs 
ceases  to  be  manifest  (v.  Bechterew  ^^). 

The  disturbances  of  equilibration  gradually  become  less 
pronounced,  but  for  many  weeks  the  animal  is  unsteady. 
This  unsteadiness  is  greatly  increased  by  covering  the  eyes. 
A  loud  sound  often  causes  the  animal  to  fall  on  the  side 
of  section  or  to  roll  round  once  or  twice.  When  both  audi- 
tory nerves  are  cut  the  animal  can  neither  stand  nor  walk. 
There  is  no  paralysis  of  the  limbs,  but  all  movements  of 
them  are  irregular  and  purposeless.     The  head  and  eyes 


128  SEMICIRCULAR  CANALS 

oscillate,  but  the  eyes  oscillate  in  a  horizontal  plane  and 
there  is  no  skew  deviation  as  when  one  nerve  is  divided. 

Various  theories  have  been  put  forward  to  explain  the 
modus  operandi  of  the  semicircular  canal  apparatus.  Thus 
actual  currents  of  endolymph  were  at  first  believed  to  be 
the  adequate  stimulus  of  the  ampullary  nerve  endings 
(Goltz^^);  then,  because  the  membranous  canals  are  of 
capillary  calibre  this  theory  was  displaced  by  that  of  partial 
pressures  (Mach/^  Breuer  ^^  and  Crum-Brown '^^)  of  the 
endolymph  in  a  certain  direction  that  is  to  or  from  the 
ampulla.  De  Cyon  "^^  differs  from  Crum-Brown,  Mach  and 
Breuer  and  considers  the  semicircular  canals  as  a  system  of 
physiological  coordinates  to  which  we  refer  all  our  notions 
of  space.  Breuer'^^  and  Ewald^^  showed  that  determination 
of  an  endolymph  current  toward  the  ampulla  produced  devi- 
ations and  displacements  of  the  head  in  a  certain  direction, 
while  determination  of  an  endolymph  current  from  the 
ampulla  toward  the  canal  produced  similar  displacements, 
but  in  the  opposite  direction.  The  existence  of  bilateral 
labyrinthine  tonus  mechanisms  which,  in  the  erect  position, 
constantly  supply  the  muscles  involved  in  equilibration  with 
tonus  impulses,  makes  the  hypothesis  of  partial  pressures 
exerted  through  the  endolymph  more  acceptable  without 
necessarily  implying  any  gross  actual  movement  of  the  fluid. 
Moreover,  the  delicacy  of  these  mechanisms  on  either  side 
of  the  body,  each  of  which  so  nicely  adjusts  itself  in  bal- 
ancing its  fellow  of  the  opposite  side  under  varying  con- 
ditions, implies  rapid  alterations  such  as  could  be  effected 
by  means  of  pressure  rapidly  transmitted  through  compara- 
tively incompressible  liquids  rather  than  by  means  of  the 
clumsy,  slow  movements  of  the  liquid  itself.  It  is  not  prob- 
able that  in  rotations  the  pressure  exerted  through  the  en- 
dolymph in  one  direction  with  reference  to  the  ampulla 
upon  one  side  of  the  body  is  reinforced  by  a  pressure  ex- 
erted in  the  opposite  direction  in  the  corresponding  canal 
upon  the  other  side. 

This  phase  of  negative  stimulation  will  therefore  be 
omitted  in  the  discussions  that  follow. 

The  otoliths,  which  in  mammifera  are  two,  and  in 
other  vertel^rates  three  on  either  side,  are,  according  toi 
Breuer  '^^   the  peripheral  organs  of  specific  sensations  of 


PHYSIOLOGY  129 

position  and  of  movements  of  translation.  They  are  dis- 
posed in  two  planes  (three  in  animals  possessing  the 
lagena)  perpendicular  to  each  other,  the  physiological 
stimulus  being  the  gravitation. 

For  the  sake  of  simplicity  and  to  avoid  confusion,  little 
mention  of  these  organs  will  be  made  in  the  discussions 
that  follow,  though  undoubtedly  they  are  affected  in  vari- 
ous forms  of  rotations  and  movements  as  well  as  in 
prolonged  aural  irrigations  and  in  strong  galvanic  stim- 
ulation. 


CHAPTER  X 

THE   EFFECTS   OF   PASSIVE   ROTATION 

Passive  rotations  were  performed  in  various  postures 
and  in  various  planes.  For  rotation  about  the  long  axis 
of  the  body,  the  subject  was  placed  in  an  arm-chair  sus- 
pended from  the  ceiling.  For  rotation  about  the  other 
axes  of  the  body,  a  broad  board,  long  enough  to  permit  the 
subject  to  li@  in  any  position,  was  suspended  after  the 
manner  of  a  boatswain's  chair. 

Passive  rotation  in  general  caused  various  disturb- 
ances depending  upon  the  duration  (repetition)  and  rapid- 
ity of  the  rotation ;  upon  the  axis  of  the  body  about  which 
the  rotation  took  place;  but,  above  all,  upon  the  abrupt 
reversal,  retardation  or  acceleration  of  the  movement. 
Mild  rotations  repeated  a  few  times  caused  merely  a 
transitory  dizziness.  If  repeated  sufficiently  often  with 
reversals,  accelerations  and  retardations,  rotations  of  mild 
degree,  i.e.,  of  short  range  and  of  a  low  rate  of  speed,  grad- 
ually produced  profound  disturbances  in  the  organism. 

Rotations  more  severe  in  grade  caused  disturbances  of 
equilibrium  with  vertigo;  displacements  and  deviations  of 
the  eyes,  head  and  body;  disturbances  of  the  circulation 
and  respiration;  disturbances  of  the  digestive  apparatus 
with  increased  flow  of  saliva,  nausea,  wretchedness  and 
vomiting;  and  finally,  disturbances  of  the  nervous  system 
varying  from  a  mild  degree  of  irritability  to  the  most  pro- 
found degree  of  general  physical  and  mental  prostration. 
The  position  of  the  body  during  rotation,  i.e.,  whether  it 
is  upright  or  horizontal,  is  an  important  factor  because  of 
the  effects  upon  the  circulation,  but,  chiefly  perhaps,  be- 
cause of  the  necessity  of  acts  of  equilibration  mediated  by 
the  otoliths  when  the  body  is  erect.  Thus  rotations  about 
the  long  axis  of  the  body  with  the  subject  sitting  upright 

130 


PHYSIOLOGY  131 

were  very  effective  in  causing  sickness  and  distress  and 
circulatory  disturbances,  whilst  with  the  subject  lying  hori- 
.zontally,  rotations  in  the  sagittal  and  coronal  planes 
caused  lighter  and  more  transient  phenomena.  It  was 
notable,  however,  that  rotation  in  the  sagittal  plane  back- 
ward, i.e.,  occiput  first,  caused  much  more  disturbance 
than  rotation  in  the  same  plane  forward,  i.e.,  face  first. 

For  convenience,  all  rotations  are  to  be  considered  as 
about  the  long  axis  of  the  body,  with  the  subject  sitting 
upright  in  an  arm-chair  unless  otherwise  specified. 

In  general,  the  effect  of  mild  rotation  upon  the  cir- 
culation is  a  rise  in  blood-pressure  dependent  on  contrac- 
tion of  the  blood-vessels.  (See  protocols  1-17  at  the  end 
of  this  chapter.)  Frequently  the  rise  is  preceded  by  a  pre- 
liminary fall  in  blood-pressure.  If  mild  rotations  be  con- 
tinued at  frequent  intervals,  the  rise  in  blood-pressure  may 
occasionally  be  absent,  owing  to  fatigue,  but  on  resting, 
and  at  times  even  without  resting,  it  will  manifest  itself 
soon  again.  After  repeated  mild  rotations,  a  close  study 
of  the  circulation  reveals  the  fact,  not  fairly  represented 
in  the  protocols,  that  the  blood-vessels  are  constantly  con- 
tracting and  dilating.  In"  severe  rotations,  the  radial  artery 
becomes  at  times  so  small  and  empty  as  to  be  impal|)able. 
Under  such  circumstances,  of  course,  the  blood-pressure  by 
clinical  methods  would  be  nil.  During  such  periods  of 
radial  pulselessness,  the  ear,  or  stethoscope,  placed  over  the 
heart  found  the  latter  beating,  with  the  sounds  feeble,  the 
second  sound  being  relativeh^  accentuated.  (See  protocol 
13).  These  pulseless  periods  occurred  mainly  in  very  rapid 
rotations  during  the  actual  rotation,  and  frequently  just 
after  reversal  or  sudden  cessation.  They  lasted  for  a  mo- 
m.ent  or  two  when  the  pulse  gradually  returned.  At  the 
time  that  the  pulseless  periods  were  observed,  the  swing 
used  consisted  of  a  boatswain's  chair.  There  was,  conse- 
quently, no  support  for  the  back,  so  that  the  subject's  head 
tilted  backward  during  the  rotation.  In  later  trials  when 
the  swing  used  (an  arm-chair)  had  a  support  for  the  sub- 
ject's back,  no  pulseless  periods  were  observed.  An  approach 
to  this  phenomenon  was  frequently  observed,  both  during 
and  after  rotations,  when  the  pulse,  at  one  moment  large 
and  with  low  blood-pressure,   would  almost  immediately 


182  SEMICIRCULAR  CANALS 

disappear  as  the  arteries  contracted  to  an  extreme  degree. 
(See  protocol  13.) 

After  long,  repeated,  mild  rotations,  or  after  severe 
rotations  with  reversals  or  retardations,  the  general  ten- 
dency is  toward  a  decline  in  blood-pressure,  with  general 
prostration  and  with  the  pulse-rate  in  general  stationary, 
or  somewhat  slowed.  Vomiting  restores  the  circulation  so 
regularly  in  rotation  sickness  that  it  may  be  regarded  as 
one  of  nature's  defences  against  failing  medullary  circu- 
lation, rather  than  as  a  mere  act  intended  to  empty  the 
stomach,  though  in  doing  the  latter  it  unquestionably 
benefits  the  general  condition  materially.  At  times  the 
blood-pressure  and  pulse-rate  made  sharp  upward  excur- 
sions before  the  vomiting  actually  occurred,  and  before  the 
'subject  was  aware  that  the  abdominal  muscles  had  become 
fixed  in  the  act.  This  fact,  not  generally  admitted  by 
physiologists  and  clinicians,  has  been  frequently  observed 
by  the  author  in  other  conditions.  The  increased  blood- 
pressure  seems  to  be  caused  by  the  same  agency  that  sets 
the  mechanism  of  nausea  and  vomiting  going,  and  is  not 
merely  the  result  of  muscular  contraction.  In  general,  the 
respiratory  rate  was  increased  during,  and  slowed  after, 
rotation.  Between  rotations,  the  rate  was  slowed  or  about 
normal,  never  much  above  it.  Severe  and  even  mild  rota- 
tions caused  complete  apnoea  for  short  periods,  followed  by 
deep  inspirations.  (See  protocols  8  and  10.)  As  a  rule,  the 
respiratory  rate  increases  as  the  blood-pressure  falls,  and 
vice  versa.  When  vomiting  and  deep  breathing  did  not 
suffice  to  maintain  or  restore  the  blood-pressure,  the  pulse- 
rate  occasionally  became  markedly  increased,  but  increase 
in  pulse-rate  apart  from  vomiting  was  the  exception,  not 
the  rule;  in  fact,  the  most  striking  general  effect  of  re- 
peated rotations  upon  the  pulse  is  a  slowing  of  the  rate. 

It  was  noted  that  covering  the  eyes  and  head  had  no 
appreciable  effect  in  preventing  the  nausea  and  circulatory 
disturbances  that  attend  rotations.     (See  protocol  2.) 

Rotations  in  the  sagittal  and  coronal  planes,  with  the 
subject  lying  horizontally,  lowered  the  blood-pressure.  (See 
protocols  17a  and  17b.)  The  pulse-rate  was  also  lowered. 
After  the  rotations,  the  blood-pressure  rose  somewhat,  but 
not  to  the  extent  observed  following  rotations  about  the 
long  axis  with  the  subject  sitting  erect. 


PHYSIOLOGY  IBB 

The  conclusions  are: 

1.  That  rotations  in  the  upright  position  about  the  long 
axis  of  the  body,  affect  the  circulation  by  irritation  of  the 
medullary  vaso-constrictor  centres.  There  are  reasons  for 
believing  that  the  semicircular  canals  are  not  in  direct  re- 
lation with  the  medullary  vaso-constrictor  centres,  and  that 
the  rise  in  blood-pressure  that  accompanies  rotations,  etc., 
is  the  result  of  the  cerebral  and  cerebellar  disturbances 
responsible  for  the  vertigo,  displacements  of  equilibrium, 
etc.  On  the  other  hand,  the  otolithic  apparatus  seems  to 
be  in  direct  relation  with  the  medullary  vaso-constrictor 
centres.  These  structures  appear  to  be  the  chief  factors 
in  the  mechanism  which  regulates  the  blood-pressure  when 
the  subject  assumes  the  erect  posture.  However,  inasmuch 
as  rotations  probably  affect  the  otolithic  apparatus  of  the 
vestibule,  as  well  as  the  ampullary  receptors  of  the  semi- 
circular canals,  it  is  probable  that  the  otoliths  are  an  im- 
portant factor  in  the  mechanism  involved  in  the  circu- 
latory changes  observed. 

2.  That  by  vaso-constriction,  the  blood-pressure  is 
raised  without  a  corresponding  increase  in  pulse-rate,  but 
when  the  rotations  are  frequently  repeated  over  long 
periods,  or  when  they  are  severe,  with  violent  reversals  or 
retardations,  fatigue  rapidly  sets  in,  with  failure  of  the 
circulation  which,  when  profound,  is  met  chiefly  by  en- 
hanced respiratory  movements  and  by  vomiting.  The 
latter  tends  to  restore  the  circulation  in  the  vital  medul- 
lary centres,  and  removes  the  stomach  contents. 

3.  That  the  vagus  (cardiac  inhibitory)  centre  is  stim- 
ulated, as  evidenced  by  the  slow  pulse,  and  in  certain 
extreme  conditions  is  so  irritated  as  to  practically  bring 
the  heart  to  a  standstill  for  a  time. 

4.  That  the  respiratory  centre  is  inhibited,  making  the 
rate  lower,  and  causing,  at  times,  complete  apnoea.  The 
subsequently  increased  depth  of  the  respiration  is  to  be 
attributed  in  part  to  a  prolonged  period  of  latency  and 
accumulation  of  C  0  2  in  the  blood. 

5.  That  the  respiratory  as  well  as  the  pulse-rate,  ac- 
companies the  blood-pressure  in  the  sharp  rise  of  the  latter 
that  occurs  with  vomiting. 

6.  That  in  rotation  in  the  sagittal  and  coronal  planes, 
with  the  subject  lying  horizontally,  the  vaso-constrictor 


134  SEMICIRCULAR   CANALS 

action  with  its  resulting  rise  in  blood-pressure,  is  wanting, 
not  because  the  rotation  does  not  stimulate  the  medullary 
vaso-constrictor  centres,  but  because  the  stimulation  of 
those  centres  is  insufficient  to  cause  appreciable  effect  on 
the  blood-pressure  on  account  of  the  diminished  tonicity 
of  the  vessels  and  lowered  pulse-rate  that  obtain  in  re- 
cumbency, these  being  due,  in  part,  to  the  inactive  state 
of  the  otolithic  apparatus. 

7.  That  in  rotations  in  recumbency,  the  vagus  centre 
is  stimulated,  as  manifested  by  lowered  pulse-rate,  which 
is  masked,  to  a  certain  extent,  because  of  the  lowered  pulse- 
rate  induced  by  recumbency. 

8.  That  a  condition  simulating  surgical  shock  may  be 
present  with  extremely  contracted  arteries.  This  seems 
to  favor  Porter's  view  of  the  mechanism  of  shock,  viz., 
arterial  constriction,  or  Henderson's  view,  viz.,  venous 
relaxation,  as  opposed  to  Crile's  view,  which  attributes 
shock  to  arterial  relaxation. 

9.  That  the  emptying  of  the  stomach  is  but  one  of  the 
bye-results  of  vomiting,  where  the  latter  occurs  as  the  re-' 
suit  of  anaemia  and  asphyxiation  of  the  medullary  centres 
in  profound  circulatory  depression  from  whatever  cause. 
Thus,  vomiting  is  to  be  regarded  as  a  response  of  the 
organism  analogous  to  that  which  occurs  in  an  animal 
upon  which  artificial  increase  of  intra-cranial  pressure  is 
practised.  In  the  latter  instance,  asphyxia  occurs  first, 
then  follows  arterial  constriction,  with  contraction  of  the 
muscles  all  over  the  body,  e,g,,  increased  peristalsis, 
arterial  constriction,  etc.,  phenomena  which  are  fairly  rep- 
resented in  the  act  of  vomiting  as  seen  in  rotations,  Yom^ 
iting,  therefore,  or  the  condition  that  immediately  precedes 
it  and  is  responsible  for  the  actual  expulsion  of  food  from 
the  stomach,  is  to  be  regarded  as  a  defence  of  the  organism 
against  threatened  dissolution  from  lowered  blood-pressure, 
and  consequent  asphyxia  of  the  medullary  centres. 

The  Influence  of  Drugs  upon  the  Circulatory  Changes 
that  Occur  with  Rotations 

Strychnin  and  atropin  in  combination  had  the  effect 
of    maintaining    the    blood-pressure    without    appreciable 


PHYSIOLOGY  135 

change  in  severe  swings  with  violent  reversals.  Protocol 
3  shows  how  this  was  effected  in  part,  i.e.,  by  increased 
pnlse-rate.  The  sensitiveness  of  the  cardiac  mechanism  to 
altered  conditions  of  intra-cardiac  pressure  is  also  well 
known.  Slight  cardiac  arh}i:hmia  was  also  noted  at  times. 
The  action  of  strychnin  alone  is  shown  in  protocol  3. 
The  blood-pressure  was  not  so  well  maintained,  nor  were 
the  effects  upon  the  subject's  general  condition  so  favourable 
as  when  the  combination  of  atropin  and  strychnin  was 
used.  Vagus  stimulation  effects  are  seen  just  after  the 
rotation.  It  is  fair  to  add  that  the  subject's  body  was  in 
a  state  of  fatigue  from  the  effects  of  a  severe  handball 
contest,  engaged  in  on  the  previous  day,  without  proper 
preparation.  Protocol  8  shows  the  effect  of  atropin,  which 
tends  slightly  to  prevent  the  marked  fluctuations  of  the 
respiratory  rate  incidental  to  rotations.  Protocol  9  shows 
the  effect  of  atropin  in  maintaining  a  good  average  stand- 
ard of  blood-pressure.  The  subject  (B),  on  whom  the 
experiments  in  this  instance  were  performed,  was  ex- 
tremely sensitive  to  rotation.  The  severe  swings  given 
after  the  atropin  could  not  have  been  tolerated  without 
the  drug.  It  should  be  noted,  however,  that  the  stomach 
was  empty,  which  is  at  times  an  important  factor  in  rota- 
tion sickness.  The  pulse-rate  was  not  quickened  in  the 
rotations  after  atropin.  This  shows  that  the  action  of 
the  drug  on  the  cardiac  vagus  terminals  was  insufficient 
to  overcome  the  effects  of  central  vagus  stimulation.  The 
blood-pressure  was  well  maintained  by  arterial  constriction 
under  the  influence  of  atropin.  Protocol  10  shows,  on 
a  different  subject  (S),  practically  what  was  shown  in 
protocol  9.  It  also  shows  the  tendency  of  the  respiratory 
rate  to  rise  as  the  blood-pressure  falls,  and  to  fall  as  the 
latter  rises.  Protocol  11  shows  the  effect  of  nitroglycerin, 
both  before  and  after  atropin.  Before  atropin  had  been 
given,  the  typical  nitroglycerin  effect  was  not  a  con- 
spicuous feature,  being  overshadowed  by  the  vaso-con- 
strictor  effect  from  the  rotations,  and  this,  notwithstanding 
that  the  subject  felt  the  usual  nitroglycerin  effects  in  the 
head.  Xitroglycerin,  administered  after  atropin,  shows  a 
marked  rise  in  pulse-rate,  illustrating  one  of  nature's 
methods  in  combating  lowered  arterial  tension.      The  large 


136  SEMICIRCULAR   CANALS 

fluctuations  of  pulse-rate  and  blood-pressure  occurring  be- 
tween the  administration  of  the  atropin  and  the  second 
dose  of  nitroglycerin  are  to  be  attributed  to  exhaustion 
of  the  neuro-vascular  mechanisms,  which  was,  in  turn,  the 
immediate  reactionary  eifect  of  the  struggle  to  maintain 
the  blood-pressure,  in  spite  of  the  relaxed  musculature  of 
the  arterioles  caused  by  the  first  dose  of  nitroglycerin. 
Protocol  12  shows  the  effects  of  strychnin  and  morphin. 
The  pulse-rate  was  not  increased,  the  blood-pressure  being 
well  maintained  by  vaso-constrictor  action,  and  yet  the 
rotations  made  the  subject  feel  very  dizzy,  sick  and 
nauseated.  With  these  there  were  motor  and  mental  de- 
pression, and  a  general  feeling  of  wretchedness.  Vomiting 
did  not  occur,  because  the  rotations  were  suspended  in 
order  to  forestall  it,  and  to  relieve  the  subject's  wretched- 
ness, which  persisted  for  over  four  hours,  partly,  perhaps, 
because  of  the  well-known  excretion  of  morphin  into  the 
stomach,  protracting  the  period  of  nausea  pending  its  re- 
absorption  or  elimination.  Protocol  13  shows  the  effect 
of  morphin  when  used  alone.  The  drug  was  administered 
after  many  rather  severe  rotations,  and  at  a  time  when 
there  was  a  steady  decline  in  blood-pressure,  with  a  ten- 
dency of  the  pulse-rate  to  rise.  Rotations  after  the  mor- 
phin showed  a  fairly  well-maintained  blood-pressure  with- 
out increase  of  the  pulse-rate.  Forty-two  minutes  after 
the  administration  of  the  morphin  the  subject  was  given 
gr  ^/(5o  of  atropin  crystals.  Fourteen  minutes  after  the 
atropin  had  been  given,  rotations  so  sickened  the  subject 
that  he  vomited.  The  blood-pressure  and  pulse-rate  failed 
to  show  the  usual  atropin  effect.  With  the  vomiting,  there 
was  the  usual  sharp  rise  in  blood-pressure  and  pulse-rate. 
A  repetition  of  the  rotation  caused  depression  of  the 
blood-pressure  and  pulse-rate,  and  the  subject  felt  nause- 
ated, dull  and  heavy.  During  a  rotation,  given  26  min- 
utes after  the  administration  of  atropin,  the  pulse-rate 
at  the  wrist  disappeared  and  the  second  sound  of  the  heart 
was  feeble  or  missing.  The  pulse  disappeared  frequently 
in  the  rotations  given  on  this  occasion,  both  before  and 
after  the  administration  of  the  drugs. 

The  effect  of  bromid  of  potassium  is  shown  in  pro- 
tocol 14a,    The  rotations  sickened  the  subject  and  caused 


PHYSIOLOGY  137 

vomiting.  Between  rotations,  the  blood-pressnre  was  fairly 
sustained.  It  can  be  seen,  however,  that  the  pulse  showed 
rather  a  tendency  to  slowing.  The  figures  do  not  fairly 
represent  the  behaviour  of  the  circulation,  as  extensive 
fluctuations  occurred,  which  were  so  evanescent  that  there 
was  not  time  to  catch  and  record  them.  After  vomiting, 
the  efficiency  of  the  circulation  was  enhanced.  With  bro- 
mid,  although  the  subject  was  sickened  quickly,  there  was 
undoubtedly  less  psychic  wretchedness  than  was  noted  in 
rotations  without  the  use  of  drugs,  whilst  between  rota- 
tions there  was  absence  of  the  usual  dread  of  the  next 
rotation. 

The  effect  of  digitalon  is  shown  in  protocol  14b.  The 
subject  felt  his  susceptibility  increased,  if  anything,  for 
the  sickening  effects  of  rotations.  The  blood-pressure 
showed  a  downward  tendency,  as  did  the  pulse-rate  after 
an  initial  rise.  The  first  rotation  was  performed  two  hours 
and  eighteen  minutes  after  the  administration  of  the  drug, 
which  was  not  sufficient  time  for  a  digitalis  preparation, 
given  hypodermically,  to  show  its  characteristic  effects  on 
the  circulation.  The  digitalon  caused  some  local  irrita- 
tion and  edema,  and  a  distinct  increase  of  stomach  irri- 
tability. The  effect  of  hyoscyamin  is  shown  in  protocol 
15.  The  drug  evidently  diminished  the  sickness  and 
wretchedness  that  usually  accompany  rotations.  There 
were  wide  fluctuations  in  the  blood-pressure  and  in  the 
pulse-rate.  On  the  whole,  with  hyoscyamin  the  blood- 
pressure  was  not  so  well  maintained  as  with  atropin,  and 
it  is  evident  that  the  drug  was  not  so  potent  as  atropin 
in  eliminating  the  effects  of  vagus  stimulation,  since  the 
pulse  showed  no  tendency  to  increase  in  rate,  and  was 
slowed,  if  anything,  after  the  rotations.  The  drug  was 
also  found  inferior  to  atropin  in  warding  off  stomach  sick- 
ness, although  it  helped  to  a  considerable  extent  in  this 
direction,  for  the  rotations  were  rather  severe,  with  many 
reversals.  The  psychic  and  motor  exaltation  noted  with 
atropin  were  missing.  During  some  of  the  rotations  an 
almost  impalpable  radial  pulse  was  found,  accompanying 
an  accentuated  second  sound.  This  was  found  repeatedly. 
Of  course,  taking  blood-pressures  under  the  circumstances 
was  out  of  the  question.     Protocol  16  shows  the  effect  of 


138  SEMICIRCULAR   CANALS 

bromid  in  a  subject  very  susceptible  to  the  effects  of 
rotation.  "Whilst  the  latter  tended  to  sicken,  there  was 
an  absence  of  the  usual  wretchedness  and  psychic  depres- 
sion. There  was  no  fear  of  being  made  sick,  and  the 
thought  of  rotations  to  come  did  not  worry.  It  was  noted 
that  in  rotations  after  bromid  the  tendency  to  nausea,  so 
readily  excited  by  the  odour  of  tobacco-smoke,  was  some- 
what lessened.  The  blood-pressure  and  pulse-rate  showed 
effects  similar  to  those  shown  in  protocol  1-i.  The  effect 
of  hyoscyamin  is  again  shown  in  protocol  16. 

The  train  of  symptoms  set  up  in  rotation  sickness  per- 
sists till  physical  and  mental  depression  ensues.  The  stom- 
ach, once  disturbed,  ever  remains  a  source  of  secondary 
irritation  to  the  medullary,  cerebellar  and  cerebral  centres. 
Hyoscyamin  counteracts  or  eliminates  the  effects  of  this 
secondary  irritation  by  depressing  the  sensory  nerve  termi- 
nals in  the  stomach.  The  drug,  however,  also  depresses 
the  psychic  areas  in  the  cerebrum.  The  bromides  act 
merely  by  depressing  the  cerebral  psychic  areas,  thereby 
eliminating  the  element  of  apprehension  and  psychic  dis- 
tress that  is  such  a  constant  symptom  in  rotation  sickness. 
Atropin  has  the  advantage  over  bromides  and  hyoscya- 
min, in  that  it  depresses  the  sensory  nerve  endings  in  the 
stomach  and  all  over  the  body,  and  at  the  same  time  stimu- 
lates the  psychic  and  motor  areas  of  the  cerebrum,  as  well 
as  the  respiratory  and  vaso-constrictor  centres  in  the  me- 
dulla. The  protocols  clearly  show  that  atropin  has  a  more 
potent  effect  than  hyoscyamin  in  tending  to  paralyze  the 
vagus  nerve  endings  in  the  heart.  However,  a  relatively 
larger  dose  of  atropin  was  used. 

The  effects  of  atropin  and  strychnin  in  combination 
are  shown  in  protocol  17,  where  the  rotations  were  per- 
formed with  the  subject  lying  horizontally.  The  effects 
are  similar  to  those  noted  in  the  rotations  performed  with 
the  subject  sitting  upright.  jSTote  the  reflex  slowing  of 
the  pulse  induced  by  recumbency,  and  the  slowing  induced 
by  vagus-centre  irritation  from  the  rotation,  and  counter- 
acted by  atropin  later  on.     (See  protocol  3.) 

These  observations  show: 

1.  That  the  coniI)ination  of  strychnin  and  atropin  is 
more  potent  tlinn  cither  of  these  drugs  used  alone,  and  ia 


PHYSIOLOGY  139 

superior  to  any  other  drug  or  combination  of  drugs  so 
far  tried  in  combating  the  effects  of  rotation  upon  the 
stomach  and  cerebrum,  and  upon  the  mechanisms  of  the 
circulation. 

2.  That  atropin,  hyoscyamin  and  bromides  are  effi- 
cient in  averting  or  ameliorating  rotation  sickness  in  the 
order  named,  atropin,  however,  being  far  more  potent 
than  hyoscyamin,  as  the  latter  is  more  potent  than  bro- 
mides, although  the  circulation  seemed  to  be  better  main- 
tained with  bromides  than  with  hyoscyamin. 

3.  That  morphin  and  nitroglycerin  are  a  hindrance, 
rather  than  a  help,  in  rotation  sickness,  and  are  contra- 
indicated  in  conditions  akin  to  rotation  sickness,  although 
with  morphin  the  circulation  was  well  maintained. 


PROTOCOLS. 
1.— On  "  S,"  a  Subject  with  Fair  Toleration.    January  1,  1909. 


Pulse- 

Blood- 

Remarks. 

rate. 

press. 

72 

120 

Normal  before  rotations. 

76 

100 

Just  after  rotation  (long  axis). 

76 

120 

1  min.  after    " 

64 

120 

P          <  (             ( <                 <  ( 

64 

95 

Just  after  rotation.    Artery  small. 

64 

120 

1  min.  after    " 

56 

120 

2 

60 

115 

3 

60 

115 

Rotation. 

96 

140 

Vomited  as  left  swing". 

84 

145 

1  min.  after  rotation. 

76 

115 

2 

72 

105 

3 

72 

110 

4         '*               «* 

72 

105 

5 

68 

105 

Rotation. 

104 

150 

Vomited. 

96 

145 

1  min.  after  rotation. 

80 

120 

2 

76 

115 

3 

80 

105 

4          **               ** 

80 

100 

5 

72 

105 

Feels  chilly. 

76 

90 

Went  to  stove. 

72 

110 

72 

100 

140  SEMICIRCULAR   CANALS 


Pulse-  Blood-  Remarks, 

rate,  press. 

72  105 

72  125      Danced  to  "warm  up." 

72  105 

72  115 

84       85      Just  after  rotation.    Eyes  open. 

64  105      1  min.  after  rotation. 

60  100 

60       95      2 

74        95 

76        95      3         *'-  " 

72  100 

76        95      4 

72  100 

72  105      5 

84  105      Rotation.     Eyes  closed. 

100  115 

80  150      Vomited. 

72  125      1  min.  after  rotation. 

80  115 

80  105      2 

80  105      3 


2. — On  "B,"  a  Very  Susceptible  Subject.    January  1,  1909 

84  120  Normal. 

84  115 

76  130  Standing  in  rowboat  as  latter  was  rowed  in  a  circle. 

88  135  Balancing  efforts  in  cold  air. 

130  No  sickening  effect. 

76  120  Normal. 

88  135  After  mild  to  and  fro  swing  in  different  directions. 

88  140 

88  140 

76  130  Just  after  rotation  long  axis. 

76  140  Nauseated. 

72  '  125  After  mild  rotation. 

68  140  1  min.  after  rotation. 

72  140  2 

72  130  3 

72  130  Resting. 

68  130 

72  135  After  mild  rotation,  eyes  closed  and  covered. 

72  125  Nauseated.     Odours  sicken. 

72  140 

80  125  After  brisk  rotation. 

68  120  Lump-sensation  in  stomach. 

140  Odour  of  tobacco-smoke  offensive. 


PHYSIOLOGY  141 

3.— On  "S,"  January  2,  1909 

Time,    Pulse- Blood-  Remarks. 

a.m.       rate,  press.  *»%-"i=u.a.B. 

76  120  Normal. 

76  115 

68  110  Mild  rotation  (long  axis). 

72  115  1  min.  after. 

68  115  2 

80  110  Mild  rotation. 

88  110  1  min.  after. 

84  110  2 

80       90  After  brisk  rotation. 

76       95  1  min.  after. 

76  110  2 

72       95  After  brisk  rotation. 

56       90  Just  after  rotation,  lying  supine. 

56       95 

64  110  1  min.  after  rot.,  lying  down. 

72  115  Standing  after  lying.    Feels  chilly. 

68  100  1  min.  after  standing  up. 

68  100 

68  100  2  min.  after  standing  up. 

60  100 

10 :  00  Strychnin  sulph.,  gr  1/20,  hypo. 

80  105  Resting. 

80  100 

72  100 

10 :  10  68  90  Brisk  rotation. 

64  95  1  min.  after. 

64  95 

64  95  2  min.  after. 

72  115  3 

10 :  zu  68  100  Brisk  rotation. 

60  100  1  min.  after. 

64  110  2 

64  110  3 

10 :  37  Atropin  sulph. ,  gr  1/100,  hyiK). 

60  95  Resting. 

64  105 

10:43     76  105 

10 :  45     72  105  Brisk  rotation,  dizzy  during  rot.  no  nausea. 

60  105  1  min.  after. 

60  105  2 

68  105  3 

72  105  4 

80  105  6 

88  105  7 

84  105  8 

11 :  00     92  105  Brisk  rotation,  dizzy ;  nauseated,  headache. 

88  105  1  min.  after. 

84  105  2 

80  105  3 


142 


SEMICIRCULAR   CANALS 


Time,     Pulse-  Blood- 
a.m.       rate,    press. 

88      105      4  min.  after. 
88      105      5 


Remarks. 


4a 

.—On  "S,"  January  3,  1909 

72 

110 

Normal,  standing. 

68 

105 

<  <            << 

56 

95 

Lying. 

52 

95 

<  < 

56 

100 

Standing. 

72 

110 

<  < 

72 

110 

After  mild  rotation  (long  axis) 

68 

115 

68 

105 

60 

105 

64 

100 

64 

95 

72 

95 

64 

105 

•60 

95 

64 

95 

64 

95 

9 

55 

Atropin  sulph., 

gr  1/100,  hypo. 

64 

95 

9 

57 

64 
56 

100 
100 

10 

00 

60 

100 

10 

02 

64 

105 

' 

10 

:05 

64 

100 

10 

09 

64 

100 

10 

10 

80 

100 

Brisk  rotation  ;  slight  momenta 

80 

100 

Nervous  ;  dizzy ;  weak  at  knees 

76 

105 

72 

105 

84 

105 

88 

100 

88 

95 

84 

95 

Lay  down. 

56 

95 

Lying  down. 

64 

100 

<  < 

68 

105 

<  < 

64 

105 

<  < 

92 

95 

Standing  after  lying. 

92 

95 
95 

<  <                 <  < 
<<                 <  < 

96 

95 

After  a  moderate  rotation. 

80 

95 

88 

100 

<<             <  (                <( 

84 

100 

tt             <<                <« 

80 

95 

<<             «< 

«< 

PHYSIOLOGY 


143 


4b.— On  «B,"  January  3,  1909 

Pulse- 

Blood- 

Remarks. 

rate. 

press. 

76 

115 

Normal,  standing. 

76 

115 

<  < 

76 

110 

Lying. 

72 

115 

<  < 

80 

110 

Standing. 

80 

110 

<  < 

92 

115 

After  a  moderate  rotation. 

80 

110 

<<                <  <               <  ( 

80 

110 

<<                tt               it 

76 

115 

tt                tt               tt 

80 

115 

tt                tt               tt 

5.— On  «S,"  January  10,  1909 

72 

110 

Normal,  standing,     • 

68 

110 

<< 

76 

115 

(« 

76 

115 

(< 

76 

115 

Lying  down. 

ao 

95 

A 

64 

105 

<f 

60 

95 

<( 

60 

105 

(( 

60 

105 

<« 

64 

105 

(« 

60 

100 

Standing, 

68 

110 

«< 

68 

100 

tt 

n 

105 

tt 

76 

110 

tt 

n 

m 

tt 

n 

110 

«f 

68 

120 

After  rotation  (long  axis). 

68 

120 

« < 

68 

115 

3  min,  after. 

68 

115 

3 

68 

110 

After  a  moderate  rotation. 

64 

105 

( «               <  <              <  < 

68 

105 

<<               <(              << 

64 

110 

After  a  brisk  rotation. 

60 

95 

1  min.  after. 

60 

95 

2 

64 

100 

3 

64 

95 

4 

68 

95 

68 

'120 

Hanging  by  legs,  trapeze  fashion. 

60 

125 

<<           <  <                  <  < 

64      130 


144  SEMICIRCULAR  CANALS 


Remarks. 


Pulse-  Blood- 
rate,    press. 

68       95      Standing. 

68  105 

68  105 

64  105 


6.— On  «S,"  January  10,  1909 

72       95      Sitting. 

72        95 

72      100 

84      110      Standing. 

88      115 

84      115 

64      100      Lying  supine. 

64      105 

64      105 

64  130  Head  lowered ;  body  making  angle  of  30°  with 
horizon.  Pupils  contracted;  face  congested; 
sense  of  pressure  over  forehead. 

64      110      Head  still  low. 

64      110 

64      105 

64      110 

68      110 

92  105  Standing  up  after  lying  with  head  low ;  pupils  di- 
lated, face  pale,  radial  artery  contracted.  On 
standing  up  blood-pressure  went  up  to  125  or 
above  it,  but  immediately  fell  to  105. 

84      105      Standing  after  lying  with  head  low. 


Head  low.     Body  making  30°  with  horizon.    Pupils 

contracted,  face  congested. 
Lying  head  low. 


On  sudden  throwing  of  subject  into  sitting  pos- 
ture. 

Sitting  after  lying  with  head  low.  Pupils  moder- 
ately  dilated,  radial  artery  small. 

Sitting  after  lying  with  head  low. 

Radial  artery  larger. 

Laughed ;  artery  smaller. 

Sitting. 


84 

110 

88 

115 

84 

115 

56 

90 

60 

95 

60 

95 

60 

95 

80 

125 

84 

110 

84 

105 

84 

105 

84 

120 

80 

115 

84 

110 

84 

105 

84 

105 

84 

125 

80 

115 

Standing,  after  sitting. 


PHYSIOLOGY 


145 


Pulse-  Blood-  Remarks. 

rate,    press. 

84      105      Standing,  after  sitting. 
95 


80 
76 
80 


64 
60 
60 
60 
64 
60 
56 
60 
60 
60 
80 


80 
80 


110 
110 


80   110 
60   90 


105 
105 
100 
100 

90 
100 
100 

95 
100 

95 
105 


84   105 
84   95 


110 
105 


Standing. 

<< 

Lying.  Pupils  small;  face  congested;  radial  ar- 
tery dilated. 
Lying. 


Lying  head  low.  Pupils  small,  etc.,  as  before. 


Standing. 


72  120 
76   115 


76 
76 
76 
72 
72 
80 


110 
110 
130 
125 
120 
125 


76  120 

76  120 

84  115 

72  110 

68  105 

68  100 

68  110 

68  105 

68  100 

68  105 

64  105 

60  115 

68  110 

64  115 


7a.— On  "B,"  January  10,  1009 

Normal,  standing. 


After  mild  rotation  (long  axis). 

1  min.  after. 

2 

After  a  brisk  rotation. 

1  min.  after. 

2 

After  brisk  swing.     Dizzy,   nauseated,  apnoea, 

followed  by  deep  inspirations. 
1  min.  after  rotation. 
2 
3 


After  mild  rotation.    Dizzy,  nauseated.    On  verge 

of  vomiting. 
1  min.  after  rotation. 
2 
After  mild  rotation.     Pulseless    at   wrist  after 

rotation.     On  verge  of  vomiting. 
1  min.  after  rotation. 
After  mild  rotation. 


Pulse-  Blood 

rate. 

press 

68 

105 

68 

100 

68 

110 

68 

105 

68 

100 

146  SEMICIRCULAR   CANALS 


Remarks. 

1  min.  after. 

After  mild  rotation.    After  a  few  turns,  was  on 

verge  of  vomiting. 
1  min.  after  rotation. 
2 
After  mild  rotation. 

Pulseless  at  wrist  for  a  moment  or  so  after  rotation. 
After  this  rotation  the  subject  did  not  recover  as  after  the  pre- 
vious rotations,  but  remained  sick  and  wretched  and  became 
yellowish  green  in  the  face.  The  odour  of  tobacco-smoke  was 
offensive.  Vomiting  did  not  occur,  as  the  rotations  were  dis- 
continued to  avert  it.  It  took  an  hour  or  more  before  the  sub- 
ject's stomach  ceased  to  distress  him. 


7b.— On  "B,"  January  17,  1909 


84 

125 

Normal,  standing. 

84 

125 

<  <             << 

76 

125 

<  (             *t 

72 

120 

Lying. 

72 

110 

<  < 

88 

115 

Standing. 

88 

120 

<  < 

88 

120 

8.— On  "  B,"  January  24, 

Respi- 

Remarks 

rations 

16 

Normal,  standing. 

16 

<  < 

18 

( ( 

16 

Normal,  lying. 

16 

<  < 

13 

Standing. 

14 

i  i 

16 

<  ( 

14 

It 

14 

4  t 

16 

(  < 

14 

Just  after  a  mild  rotation. 

16 

1  min.  after. 

18 

2 

14 

3 

18 

After  mild  rotation. 

16 

1  min.  after. 

16 

2 

18 

After  mild  rotation. 

16 

1  min.  after. 

Time,      Respi- 
a.m.      rations. 


PHYSIOLOGY  147 

Remarks. 


14  2  min.  after. 

16  3 

14  After  rotation. 

18  1  min.  after. 

16  2 

20  After  brisk  rotation. 

16  1  min.  after. 

16  After  rotation. 

12  1  min.  after. 

8  2" 

16  3 

12  After  rotation.     Left  swing  vomiting. 

16  1  min.  after. 

20  2 

18  3 

18  4 

16  5 

12  6 

10:02       16  Atropin  sulph.,  gr  1/100,  hypo. 
10:15       18 
10 :  33       16 
10 :  34       14 

10 :  35       14  After  brisk  rotation. 

14  1  min.  after. 

12  2 

14  3 

16  4         " 

14  5 

14  6 

16  7         " 

10 :  45       18  After  long,  brisk  rotation. 

14  1  min.  after. 

18  2 

16  3 

16  4 

14  5 

16  6 

12  7          " 

16  After  climbing  rope,  hand  over  hand. 

16  1  min.  after. 

14  2 

14  3 

iVbte.— Apnoea  preceded  the  vomiting.     The  rotations  given 
after   the   administration   of   atropin    drove    the    respirations 

down  to  12  or  14,  whilst  at  no  time  after  the  drug  were 
the  respirations  higher  than  18,  the  average  being  about  16. 
Even  brisk  and  prolonged  rotations  caused  no  greater  fluctua- 
tion in  blood-pressure  than  5  mm,  whilst  the  pulse-rate  never 
rose  above  70,  the  average  being  about  64,  with  a  minimum  of 
56.     After  atropin,  the  rotations  failed  to  sicken  the  subject. 


148 


SEMICIRCULAR  CANALS 


9.— On  «B,"  January  24,  1909 


Time,    Pulse-  Blood- 

a.m.       rate,  press. 

76  120 

84  115 

76  115 

72  130 

72  130 

68  115 

68  115 

68  115 

72  110 

72  150 

92  125 

72  125 

72  115 

72  110 

68  95 

72  120 

72  110 

76  115 

76  115 

76  125 

72  115 

68  110 


Remarks. 


76 
80 
76 
72 
72 
72 
10:02  72 
68 
68 
68 
68 
60 
64 
68 
68 
64 
64 
60 


10:12 


10:45 


10:45 


56 
56 
64 
68 
60 
60 


110 
135 
130 
120 
120 
115 
115 
115 
115 
115 
110 
115 
115 
115 
115 
120 
120 
110 

120 
110 
110 
105 
105 
115 


Standing. 


Lying. 


Standing. 


Hanging  by  groins  on  trapeze. 
Standing. 


After  mild  rotation. 

1  min.  after. 

After  mild  rotation. 

1  min.  after. 

After  mild  rotation. 

1  min.  after. 

After  brisk  rotation.      Lump-sensation   in 

stomach. 
1  min.  after. 
After  mild  rotation ;  sick  feeling ;  muscular 

weakness. 
1  min.  after. 

After  mild  rotation.     Left  swing  vomiting. 
1  min.  after. 
2 
3 
4 

Atropin  sulph.,  gr  1/00,  hypo. 
Resting.  » 


After  long  brisk  swing.     Practically  no  diz- 
ziness or  sickness.     Felt  strong. 
1  min.  after. 
2 
3 
4 

After  brisk  rot.  No  sickness  or  discomfort. 
1  min.  after. 


PHYSIOLOGY  149 


Pulse-  Blood- 
*  rate,    press. 

Remarks. 

60      115 

2  min.  after. 

60      110 

3 

72      125 

After  climbing  rope,  hand  over  hand 

68      125 

1  min.  after. 

64      125 

2 

64      120 

3 

The  rotations  given  the  subject  were  exceedingly  mild  and 
of  short  duration.  With  the  third  rotation,  symptoms  of  rota- 
tion sickness  set  in,  but  passed  off  almost  immediately.  The 
familiar  lump-sensation  referred  to  the  stomach  appeared  with 
the  fourth  rotation.  After  this  rotation  the  respirations  were 
slowed  to  8,  but  immediately  returned  to  16.  With  the  sixth 
rotation,  the  subject  began  to  feel  "sick  all  over."  The  stom- 
ach sickness  subsided  somewhat  immediately,  but  weakness  and 
tremulousness  in  the  limbs  persisted.  In  the  seventh  rotation 
the  subject  left  the  swing  vomiting.  The  vomiting  at  once  re- 
lieved depression  and  distress ;  the  head  became  clear  and,  in- 
stead of  being  dull  and  morose,  the  subject  became  cheerful 
and  talkative.  The  vomitus  contained  a  large  quantity  of  thick 
mucus  and  some  food.  The  vomiting  was  of  the  projectile  vari- 
ety, and  was  followed  by  a  sharp,  crampy  pain  in  the  epigas- 
trium. For  some  time  before  the  onset  of  vomiting,  there  was 
a  profuse  flow  of  saliva. 

After  atropin  rotations  had  little  effect  in  causing  even 
momentary  distress.  It  should  be  noted,  however,  that  the 
stomach  had  already  been  emptied  by  the  previous  vomiting. 
The  slow  pulse  after  atropin  was  remarkable.  Even  rope- 
climbing,  hand  over  hand,  did  not  appreciably  accelerate  the 
pulse.  Under  ordinary  conditions,  such  exertion  would  send 
the  subject's  pulse-rate  up  to  90  or  100,  or  even  higher. 


10.— On  «S,"  January  31,  1909 


Pulse-  Blood- 
rate,    press. 

Remarks. 

76      115 

Normal,  standing. 

76      115 

( <             <  < 

80      110 

<  <             <  < 

88      110 

<  <             << 

84      115 

( (             ( < 

84      110 

<<             << 

80      110 

<  (             <  ( 

80      110 

After  mild  rotation 

72      120 

1  min.  after. 

76      120 

2 

72      130 

After  rotation. 

72      120 

1  min.  after. 

84      115 

2 

76      110 

3 

150 


SEMICIRCULAR   CANALS 


Time, 

Pulse- 

Blood- 

Respi- 

Remarks. 

a.in. 

rate. 

press. 

rations 

80 

110 

4  min.  after. 

76 

Pulseless  momentarily  after  rotation. 

72 

115 

After  hard  rot.    Dizzy.    Artery  small. 

76 

105 

_  i_ 

1  min.  after. 

72 

110 

ie 

2 

72 

120 

16 

3 

72 

110 

18 

4 

72 

100 

20 

After    rot.      Dizzy;     lump-sensation; 

sick. 

68 

110 

18 

1  min.  after. 

72 

115 

16 

2 

90 

18 

After  rotation. 

120 

16 

1  min.  after. 

72 

110 

16 

2 

72 

120 

18 

3 

72 

110 

16 

4 

100 

18 

After  rotation. 

68 

120 

16 

1  min.  after. 

68 

115 

16 

2 

72 

105 

14 

3 

100 

16 

4 

68 

100 

14 

5 

76 

100 

18 

Standing. 

68 

95 

<  < 

10:21 

Atropin  crystals,  gr  1/60,  hypo. 

10:50 

88 

95 

After  standing  near  stove. 

72 

95 

Feels  well. 

72 

95 

<  ( 

72 

95 

<  < 

10:53 

68 

120 

After  hard  rotation. 

64 

120 

Momentary  dizziness   during  rotation. 

64 

115 

No  sickness  or  distress. 

68 

115 

Note. — In  general,  the  respiratory  rate  rises  as  the  blood- 
pressure  falls,  and  vice  versa. 


11.— On  "S,"  February  7,  1909 


Pulse- 

Blood 

rate. 

press 

72 

110 

72 

110 

68 

115 

72 

115 

72 

115 

68 

115 

68 

120 

68 

110 

72 

115 

Remarks. 


Normal,  standing. 


After  hard  rotation.    Dizzy.     Lump  in  stom- 
ach.    Saliva  free. 
1  min.  after. 
2 
3 


Time,    Pulse- 

Blood- 

a.m.       rate. 

press. 

68 

115 

72 

95 

68 

105 

72 

95 

68 

110 

72 

105 

PHYSIOLOGY  151 


Remarks. 

4  min.  after. 

After  hard  rotation.     Feels  like  vomiting. 

"Gone  feeling." 
1  min.  after. 
2 
3 
After  a  rest.  All  symptoms  gone  but  "lump" 

in  stomach. 


68      105 


After  rotation  nervous.     Feels  like  vomiting.     Odour  of 
alcohol  disagreeable.     Pulse  varies  from  moment  to  moment. 

Yawning.     Saliva  profuse.     Head  clear. 

100 

105  1  min.  after  rotation. 

68      110  2 

76      105  3 

90  4 

105  5  " 

72      115  6 

90  7 

105  8 

68      105  9 

9 :  29  Nitroglycerin,  gr  1/100,  hypo. 

64        95  After  nitroglycerin. 
68      100 
68      110 

68      100  Throbbing  sensation  over  forehead. 

68      105  Sick  feeling  in  stomach. 

76      110  No  nausea.     Feels  chilly, 
76      100 

9  :  37     72      100  After  rotation  pulse  did  not  disappear. 

9 :  38     76      115  Feels  like  vomiting.     Feels  exhausted 

9 :  39     76      105  Headache,  nausea. 
9:39^   76      115 

9 :  40     76      110  ^Feels  well,  but  has  frontal  headache. 

9 :  41     76      105  After  rot.     Sick,  nervous,  chilly,  shivering. 

9:42     72      110  Artery    large.      Pulse    easily  felt,   but    of 

Corrigan  type. 
9 :  43     72      105 

9 :  44     72      105  Head  clear. 

10:03  Atropin  crystals,  gr  160,  hypo. 

10:12  80  Wretched  and  shivering.     Hard  to  find  radial 

artery.      Heart's    first    sound    long     and 
booming. 
10 :  13     80        90 

10 :  17     96      105  After  exercise  (dancing)  pupils  contracted, 
10:18     76      105      Headache  (vertex).     Lump  in  stomach. 
10 :  19     84        95      Head  has  not  cleared  yet. 
10 :  20     38       95 


152  SEMICIRCULAR   CANALS 


Time,     Pulse-  Blood-  Remarks 

a.m.        rate,     press.  itemarKS. 

10 :  30  80  95  Pain  in  forehead  and  in  left  of  epigastrium. 
This  latter  was  present  before  the  experi- 
ments were  begun. 

10 :  31     88        95 

10:32  88  105  After  rotation.  Pulseless  at  first.  No 
nausea.     Feels  well. 

10 :  33     88        85      Pulse  comes  and  goes.     Artery  very  small. 

10 :  34     88        80 

10 :  42  After  rotation.     No  bad  effects.     No  pres- 

sures taken. 

10 :  47     92        95      Feels  very  well.     Talkative.     Resting. 
88      110 
80      115 
88      115 

10 :  52     84      105      After  rotation.     Pulseless  at  first. 

84      100      Momentary  dizziness.     No  nausea  or  ten- 
dency to  vomit. 
72      105 

10 :  57  Pulse   varies    markedly    in    force,    and   at 

times  seems  to  disappear. 

10 :  58  Nitroglycerin,  gr  1/100,  hypo. 

10:58^   84        85      Feels  well. 

10 :  59     80        90      Headache  returning. 

11 :  00     96        90 

11 :  01     92        95 

11:02     88        95 

11 :  05  84  95  After  rotation.  No  sickness  or  distress 
from  rotation. 

11 :  06     92      105 

11 :  07     92      105      Pulse  did  not  disappear. 

11 :  08     96      105 

Note. — Nitroglycerin  prevented  marked  fluctuation  of  the 
blood-pressure  after  rotations,  possibly  by  its  effect  in  maintain- 
ing equalized  intra-cardiac  pressure.  Atropin,  by  counteract- 
ing the  dilatation  of  the  arterioles,  caused  the  fluctuations  in 
blood-pressure  to  reappear.  After  the  second  dose  of  nitro- 
glycerin the  fluctuations  in  pressure  were  again  partially  sup- 
pressed. 


12.— On  "B,"  February  12,  1909 


80 

120 

Normal,  standing. 

76 

120 

<  <                <  < 

76 

120 

<  4                                    <  < 

76 

110 

<  <                                    <  < 

After  rotation  dizzy,  fulness  in  head,  chilly, 
momentary  pulselessness. 

76 

105 

1  min.  after. 

76 

115 

2 

Time, 

Pulse- 

Blood- 

a.m. 

rate. 

press. 

80 

100 

PHYSIOLOGY  153 

Three  rotations  were  given  to  note  the  variations  of  the 
pulse  and  the  accompanying  symptoms.  During  the  first,  which 
was  a  mild  rotation,  the  pulse  disappeared  and  returned  many 
times.  There  was  no  nausea  or  distress  in  the  head  at  first. 
After  a  time  the  lump-sensation  was  felt  in  the  stomach,  and 
with  it  fulness  in  the  head  and  dizziness.  Vertigo  was  aggra- 
vated by  looking  up  over  head,  but  not  on  looking  at  things 
straight  in  front.  During  the  second  rotation  the  pulse  did  not 
disappear,  but  the  artery  became  extremely  contracted,  with 
apparently  well-maintained  blood-pressure.  The  subject  was 
nauseated  and  on  the  verge  of  vomiting.  These  symptoms  dis- 
appeared when  the  swing  was  stopped.  In  the  third  rotation 
it  was  found  that  the  effects  of  rotation  could  be  better  resisted 
if  the  eyes  were  kept  closed.  Opening  the  eyes  during  a  rota- 
tion precipated  the  subject's  sickness.  During  the  rotation  the 
pulse  did  not  disappear,  but  afterward  the  artery  became  very 
small  and  at  times  the  pulse  could  not  be  felt.  When  the  pulse 
returned,  the  artery  was  dilated  and  the  pressure  low.  During 
the  rotation  there  was  a  marked  tendency  to  vomit.  After  the 
rotation  recovery  was  slow  and  incomplete. 

Remarks. 

After  rotation.  The  pulse  persisted  through 
the  rotation,  but  the  pressure  seemed  to 
be  low.  Resting  the  head  against  the  rope 
retarded  the  sickness.  The  subject  was 
very  wretched  on  the  swing,  had  frequent 
eructations,  and  was  on  the  verge  of 
vomiting.  After  the  rotation  the  subject 
felt  weak  and  wretched  and  wanted  to  lie 
down,  or  even  to  put  his  feet  somewhere  to 
rest  them. 

9 :  45  . .  . .  Strychnin  sulphate,  gr  1  30,  hypo.  The  sub- 
ject felt  no  pain  from  the  hypo.  Recovery 
was  slow  after  the  last  rotation.  The  sub- 
ject felt  weak  and  disinclined  for  work. 
He  felt  loss  of  control  of  the  movements 
of  the  head  when  the  latter  was  tilted  from 
side  to  side.     Flatus  was  passed. 

9 :  52     . .         . .      Knee-jerks    slightly    overactive.      Achilles 

jerk  absent.     The  subject  went  and  stood 

by  the  hot  stove.     This  caused  return  of 

the  lump-sensation  and  stomach  distress. 

Normal. 
<  < 

After  rotation. 

Morphin  sulphate,  gr  1'6,  hypo. 

Head  clear.    Feels  well.     Pupils  contracted. 


f-4f*--  r# 


10: 

;11 

64 

100 

10: 

:12 

64 

100 

10: 

;13 

64 

105 

10: 

:18 

10: 

;30 

64 

130 

10: 

:31 

68 

135 

10: 

:32 

64 

130 

.10: 

:33 

64 

130 

10: 

:34 

64 

130 

154  SEMICIRCULAR   CANALS 


Time, 

Pulse- 

Blood- 

Remarks. 

a.m. 

rate. 

press. 

10:35 

72 

130 

After  rotation.     Nausea. 
Muscular  inefficiency. 

10:36 

72 

125 

1  min.  after. 

10 :  37 

76 

120 

2 

10:38 

76 

120 

3 

10:46 

68 

120 

After  mild  rotation. 

10:47 

68 

120 

10:48 

68 

120 

Subject  became  green  in 

Lump-sensation. 


sick.     Markedly  nervous  and  weak,  espe- 
cially in  the  legs.  Brain  tired  and  clouded. 
On  the  verge  of  vomiting. 
The  rotations  were  discontinued  to  avert  vomiting.     This 
probably  had  much  to  do  with  prolonging  the  subject's  sickness, 
for  it  was  fully  four  hours  before  the  subject  felt  himself  again. 
It  is  evident  that  the  immediate  effects  of  rotation  sickness 
are  not  dependent  on  circulatory  impairment;  for,  in  spite  of 
well-maintained  pulse-rate  and  blood-pressure  after  the  admin- 
istration of  morphin,  the  susceptibility  of  the  subject  to  rota- 
tion sickness  was  enhanced. 

13.— On  «S,"  February  14,  1909 

76      115      Normal,  standing. 

72  115 
Two  rotations  were  given  without  taking  observations  on 
the  pulse-rate  and  blood-pressure.  In  the  first  rotation  there 
was  slight  dizziness,  and  the  pulse  almost  disappeared,  but 
gradually  returned  with  full  force.  In  the  second  rotation  the 
pulse  did  not  disappear,  but  the  artery  was  much  constricted. 
The  heart-sounds  were  normal,  the  second  aortic  having  a  well- 
marked  click.  There  was  some  dizziness,  with  increased  sali- 
vary flow.     Recovery  was  prompt. 

68      110      Normal,  standing. 

68  115 
Two  rotations  were  given  with  the  eyes  closed  and  covered, 
and  with  the  auditory  canals  plugged  tightly.  The  first  was  a 
hard,  brisk  rotation.  The  pulse  did  not  seem  to  change  during 
the  rotation.  There  was  no  dizziness  nor  distress.  Only  a  soft, 
soothing  motion  was  experienced,  though  the  saliva  was  pro- 
fuse. During  the  second  rotation  the  pulse  almost  disappeared, 
but  soon  returned  with  full  force  and  constricted  arteries.  The 
rate  at  this  time  was  68.  The  salivary  flow  was  profuse,  and 
there  was  dizziness  and  commencing  lump-sensation  in  the 
stomach.  When  the  swing  was  stopped  the  subject  felt  that 
he  was  still  turning.  Tactual  impressions  were  the  only  means 
he  had  of  knowing  whether  he  was  moving  or  not.  The  radial 
artery  was  dilated,  and  its  wall  quickly  receded  after  the  up- 
stroke of  the  pulse,  suggesting  the  Corrigan  pulse.  The  subject 
felt  himself  getting  sicker  and  sicker, 


PHYSIOLOGY  155 

TT'    ^«lr?!^S"  Remarks, 

a.m.       rate,    press. 

64      115      2  min.  after  rotation. 
72      110      3 

Two  rotations  were  given  with  the  eyes  closed  and  the  ears 
plugged.  In  the  first  rotation,  which  was  a  mild  one,  the  sub- 
ject experienced  dizziness  and  lump-sensation  in  the  stomach. 
He  yawned  much,  and  the  salivary  flow  was  profuse.  In  the 
second  rotation  the  pulse  did  not  disappear,  but  it  became  very 
small  and  scarcely  perceptible.  The  second  aortic  sound  was 
lengthened  and  loud.  The  first  sound  seemed  feeble.  The  up- 
stroke of  the  pulse  was  feeble.  Three  minutes  later  the  rate 
was  64,  and  the  blood-pressure  115,  and  then  the  second  aortic 
sound  was  clear  and  distinct  as  compared  with  one  minute  pre- 
viously, when  the  pulse  was  feeble  and  the  second  aortic  sound 
almost  inaudible.  There  were  quick  and  wide-ranging  varia- 
tions in  the  blood-pressure.  The  subject  felt  chilly  along  the 
spine,  and  yawned  frequently.  The  salivary  flow  was  profuse. 
No  lump-sensation  was  experienced,  but  there  was  a  constant 
tendency  to  "gag." 

64      115      3  min.  after  rotation. 

Morphin  sulphate,  gr  1  6,  hypo. 
Chilly  and  nervous.     Some  nausea. 
Artery  small.     Lump  sensation. 
Eructations.     Pain  in  epigastrium. 
Numbness  in  hands.     Feels  tired. 
First  heart-sound  feeble  and  short,  with  in- 
distinct second  sound.     Feeling  of  tight- 
ness across  forehead.    Slightly  nauseated. 
After  rotation. 

During  the  rotation  the  first  heart-sound  was  scarcely  audi- 
ble. The  second  sound  was  fairly  audible,  but  there  was  no 
snap  at  the  closure  of  the  valves.  The  pulse  did  not  disappear, 
but  it  became  very  feeble.  The  subject  became  dizzy  and  nause- 
ated, and  was  on  the  verge  of  vomiting.  Recovery  was  much 
retarded  as  compared  with  other  rotations. 

10 :  07     68      105 

10 :  12     68      115      The  radial  artery  was  not  so  constricted  as 
previously.    The  first  heart-sound  was  fee- 
ble. There  was  no  pain  nor  lump-sensation 
in  the  stomach.     The  subject  felt  well. 
10 :  14     During   a  rotation  there  was   slight  dizziness,  but  no 
nausea  or  lump-sensation.    The  subject  felt  well,  but 
"the  brain  was  clouded."     The  pulse  did  not  disap- 
pear.    The  artery  was  small,  and  the 'pressure  well 
maintained. 
10 :  15     During  a  rotation  the  subject  was  not  made  dizzy  or 
sick,  and  it  did  not  distress  him  to  look  at  objects. 
The  stomach  felt  well,  but  the  saliva  was  increased. 
10 :  18     A  very  brisk  rotation  was  given.    In  this  rotation  the 


9; 

:52 

9: 

:53 

72 

lio 

9: 

:55 

72 

100 

9: 

;57 

76 

110 

9: 

:59 

72 

100 

10: 

:01 

68 

95 

10: 

:04 

68 

100 

10: 

:05 

68 

105 

166  SEMICIRCULAR   CANALS 

subject's  head  extended  backward  so  that  his  body 
approached  the  horizontal  plane.  During  the  rota- 
tion the  subject  felt  no  sickness  or  distress.  The 
pulse  disappeared  at  first,  but  soon  returned.  The 
heart-sounds  were  fairly  normal,  but  the  rate  was 
considerably  slowed.  One  minute  after  the  rotation 
the  subject  began  to  get  sick.  The  lump-sensation  in 
the  stomach  returned  and  with  it  nausea.  The  subject 
became  sicker  and  sicker,  until  his  wretchedness  be- 
came extreme. 

Time,    Pulse-  Blood-  Remarks. 

a.m.       rate,    press.  xvciii«M.n.D. 

10:25     ..        90      Nervous.     "Heartburn." 

10 :  26      . .        95 

10 :  27      . .      100      Brain  clouded. 

10 :  28     64      100      No  lump-sensation. 

10:29  64  105  After  rotation.  Artery  extremely  small. 
Dizziness.  Nausea.  Lump-sensation.  On 
the  verge  of  vomiting.  Listless.  Wants 
to  lie  down. 

10 :  30     64      110      1  min.  after  rotation. 

10:31     64      110      2 

10 :  34  Atropin  crystals,  gr  1/60,  hypo. 

10 :  35  64  95  Mist  over  eyes.  Otherwise  well.  No  nausea. 
No  dizziness. 

10 :  37  64  105  Feels  better.  Eyes  clearing.  Stomach  feels 
well.  No  lump-sensation.  Feels  that  he 
is  recovering. 

10 :  40      . .        95 

10 :  41     64        90      Artery  almost  impalpable. 

10:42  64  105  Artery  small.  Feels  well,  but  has  slight 
mist  over  eyes. 

10 :  44     64      100      Does  not  feel  well. 

10 :  45      . .      105      Feels  nervous. 

10 :  48  A  rotation  was  given.  The  subject  became  dizzy  and 
nauseated,  and  finally  vomited.  One  minute  before 
vomiting  occurred  the  arteries  became  contracted  and 
the  blood-pressure  rose  to  120,  but  the  subject  said 
that  there  had  already  been  some  contractions  of  the 
abdominal  muscles.  After  the  vomiting  the  blood- 
pressure  was  120,  with  extremely  constricted  arteries. 
The  head  felt  light.  The  mouth  was  dry  ;  the  heart- 
beats were  strong,  but  irregular  in  rhythm.  The 
stomach  felt  well,  but  the  subject  felt  nervous  and 
had  "heartburn." 

10:50     80      115      After  vomiting. 

10 :  53     64      105 

10 :  54     68      105 

10 :  56     60      110 

10 :  57     68      110 

11 :  00  A  brisk  rotation  was  given.  The  pulse  disappeared. 
The  second  aortic  sound  wag  inaudible  at  times,  and, 


PHYSIOLOGY  157 

at  other  times  scarcely  audible.  The  subject  expe- 
rienced no  dizziness,  and  only  slight  nausea.  His  vol- 
untary muscular  power  seemed  to  be  good.  During 
the  rotation,  the  eyes  were  the  chief  source  of  dis- 
tress. He  experienced  some  lump-sensation  in  the 
stomach  at  times,  and  at  other  times  he  was  quite 
free  from  it.  Recovery  was  somewhat  retarded.  The 
subject  felt  nervous. 

Remarks. 


Time, 

Pulse-  Blood- 

a.m. 

rate. 

press. 

04 

85 

After  rotation. 

05 

105 

<  < 

06 

60 

95 

tt 

07 

, 

100 

** 

08 

60 

100 

<  ( 

09 

,  ^ 

.  , 

Feels  dull  and  Y 

'Y-  Has  no  nausea.  Stom- 
ach feels  well.  Voluntary  muscular  power 
is  good.  • 


14a.— On  "S,"  February  21,  1909 

7 :  15      . .         . .      Bromid  of  potassium,  gr  Ix.,  per  os. 
8:45     80      110      Normal,  standing. 
8:46     76      110 

8 :  51     Rotation.     Slight  dizziness.     Pulse  did  not  disappear. 
Saliva  increased.     Eyes  distressed  subject. 
64      120      After  rotation. 
72      120 
8 :  55       Rotation.     Very  dizzy.    Nauseated ;  salivary  flow  pro- 
fuse. Pulse  did  not  disappear,  but  arteries  contracted 
and  dilated.    The  blood-pressure  varied.    Pulse  of  the 
Corrigan  type  at  times. 
68      120      After  rotation. 
64      105 
9:04       Rotation.     Pulse   did   not   disappear,  but   the   radial 
artery  became  very  small.     Very  dizzy.     No  lump- 
sensation.     Eructations.     Distress  in  eyes. 
72      120      After  rotation. 
72      115 
9 :  07      Rotation.     Dizziness,  heartburn,    eructations.      Pulse 
did  not  disappear.  Rapid  fluctuation  in  pressure,  which 
was  as  low  as  90  at  times.     The    subject's   distress 
quickly  disappeared,  although  the  fluctuations  in  the 
blood-pressure  persisted. 
64      115      After  rotation. 
68      110 
9:12       Rotation.     Very  sick  and  dizzy.     Eructations,  flatus. 
Twitching  in  the  left  upper  eyelid.  Saliva  profuse. 
Lump-sensation.   Recovery  quick.    Pulse  did  not  dis- 
appear, but  was  very  small.  Subject  was  chilly  and 
felt  as  if  going  to  vomit. 


158  SEMICIRCULAR   CANALS 


Time,    Pulse-  Blood-  Remarks, 

a.m.      rate,    press. 

68      115      After  rotation. 

72      105 

68      115 
9 :  17     Rotation.    Nauseated  and  dizzy.    On  the  verge  of  vom- 
iting.    Nervous.     Pulse  did  not  disappear. 

68      120      After  rotation. 

68      120 

72      110 
9 :  25     Rotation.      Became   nauseated  and  vomited.      Subject 
felt  his  skin  hot.    Pulse  did  not  disappear.    Nervous. 
Head  clear. 

80      125      After  vomiting. 

80      115 

72      120 

72      120 
9 :  38     Rotation.     Slight   dizziness.     No  sick  feeling.     Quick 
recovery.     Feels  a  little  weak  and  nervous,  but  this 
does  not  worry  him.    Stomach  gives  slight  intimations 
of  disturbance.    Saliva  about  normal. 

68      120      After  rotation. 

68      120 

68      110 

68      115 

68      115 
9 :  40    Rotation.     Nauseated,  weak,  and  dizzy ;  chilly ;  nervous 
and  weak.     Feels  as  if  there  is  gas  in  the  stomach. 
Difficult  to  keep  eyes  open. 

68      120      After  rotation. 

64   120 

64   120 

68   115 


14b.— On  "B,"  February  21,  1909 

7:40  Digitalin,  minims  XV.,  hypo. 

7:45     72      125 
80      120 
76      120 
9 :  52     80      110 
80      110 
84      105 
9  :  58     Rotation.    The  subject  was  made  very  dizzy.    When  the 
swing  was  stopped  he  felt  himself  rotating  in  the  op- 
posite direction.     The  pulse  did  not  disappear. 
88      110      After  rotation. 
76      110 
10 :  07     Rotation.     Very  dizzy.      On  the  verge   of  vomiting. 
Weakness  about  the  eyes    and   wretched   feeling   in 
head.     The  subject  felt  that   he  was   more   suscep- 


PHYSIOLOGY  159 

tible  than  usual  to  the  effects  of  rotation.  The  mere 
thought  of  the  swing  made  him  wretched.  The  pulse 
did  not  disappear.  The  time  allowed  between  the  ad- 
ministration of  digitalin  and  the  rotations  was  per- 
haps insufficient  to  secure  full  action  of  the  drug. 

Time,    Pulse-  Blood-  Remarks 

a.m.      rate,    press.  Kemarks. 

76      100      After  rotation. 


15.— On  "S,"  February  22,  1909 

9:15     76      115      Normal,  standing. 
72      115 

Rotation.  Radial  artery  dilated  during  rotation.  Dizzy. 
Pulse  did  not  disappear.  On  stopping  the  swing  ex- 
ternal objects  seemed  to  move  in  the  direction  oppo- 
site to  that  of  the  rotation.  Just  after  the  rotation 
the  radial  artery  became  small, 

68      120      After  rotation. 

Rotation.     Dizziness,  but  no  nausea  or  sick- 
ness.    Pulse  did  not  vary  much. 
68      110      After  rotation. 

Rotation.  Dizzy,  nauseated,  lump-sensation,  on  the 
verge  of  vomiting.  Saliva  profuse.  Recovery  slow. 
Beginning  to  feel  nervous.  Pulse  remained  and  was 
large  and  soft.  After  the  rotation  the  radial  artery 
contracted  and  dilated,  and  the  blood-pressure  varied 
from  moment  to  moment,  being  at  times  as  low  as  90. 
The  subject  felt  sick  and  wretched.  He  was  chilly 
and  nervous,  yawning  from  time  to  time. 


68 

125 

After  rotation. 

64 

115 

64 

115 

68 

120 

^  ^ 

110 

115 

110 

80 

110 

Rotation.      Very  dizzy.     On   the  verge   of  vomiting. 
Heartburn.     Saliva  profuse.     Hiccough  (after  pres- 
sures were  taken).     Pulse   became  very   small   and 
hard.     Eructations,  lump  sensation,  grogginess. 
64      120      After  rotation. 
78      105  " 

..      110 
..      105 
..      115 
9:57     64      110      Normal,  chilly,  nervous. 

72      105      Pulse  irregular  in  rhythm. 
9 :  58  Hyoscyamin,  gr  1100,  hypo. 


160  SEMICIRCULAR   CANALS 

^^   ^"Ir  ni^"  Remarks, 

a.m.      rate,    press. 

9:59     56      100 

10 :  45  . .  . .  Pulse  irregular  in  rhythm,  especially  on  deep 
inspiration.  Feels  chilly.  Temperature  of 
air  28°  F. 

10:46     52      100      Normal,  standing. 
60      100 

10 :  50  Rotation.  Dizziness.  Heavy  feeling  across  forehead. 
Pulse  slow  and  feeble.  Pupils  contracted.  No  nausea 
or  sickness.  External  objects  seemed  to  move  about 
the  subject's  body  in  the  horizontal  plane. 

10 :  54     Rotation.     Very  dizzy.     Momentarily  nauseated.     No 
lump-sensation.     No    excess   of    saliva.      Recovery 
prompt, 
52      100      After  rotation. 
52      110 
56      110 

11 :  00  Rotation  prolonged  and  brisk,  with  reversals.  Dizzy  at 
reversals,  but  the  feeling  passed  off  immediately. 
Toward  the  end  the  subject  felt  as  if  he  would  fall 
out  of  the  swing.  Slight  mist  before  eyes.  Momen- 
tary nausea  after  each  swing.  After  the  rotations 
the  subject  had  eructations  and  heartburn,  and  felt 
sick.  In  a  moment,  however,  he  felt  well,  but  had 
intimations  of  an  oncoming  headache.  He  had  a  faint 
feeling  in  the  stomach  as  if  he  had  indigestion,  but 
there  was  no  accompanying  feeling  of  wretchedness. 
He  had  not  the  usual  feeling  of  exhaustion.  He  had 
no  dread  of  the  swing  "because  there  was  no  feeling 
to  it"  after  the  hyoscyamin. 

11 :  02     52        80      After  rotation. 

11:03     52        95 

11:04     52      105 

11:06     60      110 

11:07     56      100 

11 :  17  Rotation.  As  the  swing  stopped  the  subject  was  on  the 
verge  of  vomiting.  The  usual  symptoms  were  pres- 
ent, viz.  :  dizziness,  heaviness  in  head,  lump  sensa- 
tion in  stomach,  increased  saliva.  The  pulse  disap- 
peared during  the  rotation,  and  the  second  aortic 
sound  was  almost  inaudible.  Recovery  was  prompt. 
The  subject  felt  chilly,  but  was  not  nervous. 

11 :  18     56       95      After  rotation. 

11:19     56      100 

11:20     52        95 

11:21      ..95 

11 :  37  Rotation.  Dizzy.  Inclined  to  vomit.  Lump-sensation. 
Recovery  slow.  Slight  heartburn.  Beginning  to  fear 
swing.  During  the  rotation  the  pulse  disappeared  at 
the  wrist,  but  the  aortic  second  sound  was  more  pro- 
nounced and  snappy  than  before  the  rotation. 


PHYSIOLOGY  161 

Time.    Pulse-  Blood-  Remai-ks. 

a.m.      rate,    press. 

11 :  38     . .      100      After  rotation. 

11:39     64        95 

The  rotations  given  after  hyoscyamin  were  long  and 
brisk  as  compared  with  the  rotations  given  before  the 
hyocyamin,  and  yet  the  subject  readily  recovered 
from  their  effects.  When  the  arteries  were  extremely 
contracted  the  blood-pressure  apparatus  was  ineffi- 
cient. An  accentuated  second  aortic  sound  was  re- 
peatedly found  to  accompany  an  almost  impalpable 
radial  pulse. 

16.— On  "B,"  February  22,  1909 

7 :  25     . .         . .      Potassium  bromid  gr  Ix.,  per  os. 

10:00     72      105      Normal.     Watery,  metallic  taste  in  mouth. 
76      105 
72      105 

10:04  Rotation.  Dizziness  and  distress,  especially  referable 
to  eyes.  No  sick  feeling  on  reversals.  On  looking 
up  and  down,  external  objects  seemed  to  move  with 
a  wavy  up-and-down  motion.  Slight  lump-sensation 
in  stomach. 

10:08  Rotation.  Pulse  showed  little  variation  and  did  not 
disappear.  During  the  rotation,  looking  overhead 
caused  extreme  dizziness.  Lump-sensation.  Recov- 
ery prompt,  but  subject  is  afraid  of  the  swing. 

10 :  10  Rotation.  On  the  verge  of  vomiting,  but  no  feeling  of 
wretchedness  and  no  dread  of  the  swing.  The  subject 
was  satisfied  to  go  on  with  the  rotations  until  vomiting 
should  occur.  Recovery  prompt.  Odour  of  tobacco- 
smoke  not  offensive.  Lump-sensation  referred  to  the 
stomach.  The  pulse  did  not  disappear  during  the  ro- 
tation, but  the  artery  was  contracted. 

10:12     80      120      After  rotation. 

10:13     76      100 

10 :  19  Rotation.  Lump-sensation.  On  the  verge  of  vomiting. 
Only  a  slight  feeling  of  sickness.  Not  afraid  of  swing. 
No  mental  depression.  Odour  of  tobacco-smoke  nause- 
ates.    Eructations. 

10 :  21      . .       100      After  rotation. 
10:22      ..       105 
10 :  23     72      115 
10 :  24      . .       110 

10 :  39  Hyoscyamin,  gr  1/100,  hypo. 

11 :  39     Lump-sensation.     Very  dizzy,  on  the  verge  of  vomit- 
ing.   Recovery  prompt,  but  lump-sensation  persisted. 
Mouth  not  dry.    Pulse  56  at  11 :  40,  11 :  42,  and  11 :  43. 
The  rotations  given  after  the  bromid  would,  under  ordi- 
nary circumstances,  have  sickened  the  subject.    The  absence 


162 


SEMICIRCULAR   CANALS 


of  psychic  depression  and  fear  of  the  swing  were  noteworthy, 
and  must  be  attributed  to  the  effect  of  the  bromid. 

The  rotation  given  after  hyoscyamin  was  of  the  same  du- 
ration and  intensity  as  the  rotations  given  the  same  subject  on 
another  occasion  after  atropin,  when  no  disagreeable  effects 
were  suffered.  It  should  be  remembered,  however,  that  on  that 
occasion  the  subject  had  previously  vomited.  This  fact  tends 
to  offset  somewhat  the  apparent  superiority  of  atropin  in  pre- 
venting rotation  sickness. 


17a.— On  "S,"  May  21,  1909 


Time, 

Pulse-  Blood- 

Remarks. 

a.m. 

rate. 

press. 

9:56 

64 

105 

Normal,  sitting. 

68 

105 

<  < 

64 

105 

<  ( 

10:09 

52 

105 

Lying  on  back  in  swing. 

56 

105 

<  <               <  < 

52 

105 

tt              *( 

52 

105 

tt              tt 

10:38 

52 

90 

After  double  rotation  in  cor 

10:54 

52 

90 

<  <                       < 

48 

90 

1  min.  after. 

48 

95 

2 

48 

95 

3 

11:01 

52 

95 

Resting. 

48 

95 

<  < 

48 

100 

<  < 

11:04 

44 

95 

After  hard  rotation  in  coror 

11:05 

44 

95 

<  <                         <  ( 

11:06 

44 

95 

tt                         tt 

11:07 

44 

59 

tt                         tt 

11:10 

44 

85 

tt                         tt 

11:11 

48 

90 

tt                         ■« 

11:12 

44 

100 

tt                         t$ 

11:13 

44 

105 

tt                         i< 

11:14 

48 

115 

tt                         tt 

11:18 

48 

105 

tt                         tt 

11:19 

48 

105 

t*                         tt 

11:20 

48 

105 

tt                         tt 

11:21 

48 

105 

tt                         tt 

17b— On  "S,"  June  6,  1909 

7:20 

•• 

•• 

Atropin   sulphate,   gr  1/75, 
trate,  gr  1/40,  both  hypo. 

8:40 

120 

110 

After  mild  exercise. 

108 

110 

« < 

108 

110 

<  < 

100 

110 

■■ 

Strychnin  ni- 


PHYSIOLOGY 


163 


Time, 

Pulse- 

Blood 

a.m. 

rate. 

press. 

9 

18 

72 

95 

9 

19 

68 

95 

Q. 

22 

64 

105 

9 

23 

60 

105 

9 

27 

60 

95 

9 

28 

60 

100 

9 

30 

60 

105 

9 

31 

64 

105 

9 

32 

56 

95 

9 

33 

56 

100 

9 

37 

56 

95 

9 

38 

60 

100 

9 

39 

60 

110 

9 

40 

60 

105 

9 

41 

60 

105 

9 

50 

56 

90 

9 

51 

52 

95 

9 

52 

56 

100 

10 

10 

56 

115 

10 

11 

56 

115 

10 

12 

56 

110 

10 

13 

56 

105 

10 

14 

56 

115 

10 

■15 

56 

105 

10 

16 

56 

115 

10 

:20 

80 

90 

Remarks. 

After  rotation  in  coronal  plane. 


Resting. 


Asleep. 


After  rotation  in  coronal  plane 
Asleep. 

After  rotation  in  coronal  plane. 


Resting. 


CHAPTER  XI 

THE  EFFECTS   OF   ROTATION   UPON  THE  DIGESTIVE 

APPARATUS 

A  very  constant  effect  of  rotations  was  stasis  of  the 
stomach  contents.  Numerous  test  meals  were  given,  both 
with  and  without  drugs,  and  in  no  instance  was  there 
evidence  of  even  liquids  escaping  into  the  intestine.  On 
the  other  hand,  the  cardiac  sphincter  was  usually  relaxed, 
for  eructations  were  frequent.  In  all  the  rotations  per- 
formed with  the  subject  sitting  upright,  i.e.,  about  the 
long  axis,  the  amount  of  chyme  withdrawn  one  hour,  in 
some  instances  two  hours,  after  an  Ewald  test  meal  (con- 
sisting of  two  ounces  of  bread  and  eight  ounces  of  water), 
was  always  some  ounces  in  excess  of  what  had  been  in- 
gested. In  these  rotations  it  was  noticeable  that  the  sali- 
vary flow  was  always  increased,  with  marked  nausea,  and 
at  times  a  perversion  of  the  sense  of  smell.  In  the  rota- 
tions with  the  subject  lying  horizontally,  when  the  rota- 
tion was  in  the  sagittal  plane  the  saliva  was,  in  some  in- 
stances, still  somewhat  increased,  and  the  chyme  withdrawn 
excessive  in  amount  (e.g.,  o^iv).  Nausea  and  distress 
referable  to  the  stomach  were  not  a  feature  in  sagittal 
and  coronal  rotations,  but  the  stomach  was  profoundly 
affected,  as  shown  by  the  fact  that  the  subject  vomited 
when  he  left  the  swing.  In  horizontal  rotations  in  the 
coronal  plane,  and  in  mild  rotations  in  the  sagittal  plane, 
the  amount  of  chyme  withdrawn  was  considerably  dimin- 
ished, compared  with  that  withdrawn  after  rotations  in 
other  planes,  and  this  in  spite  of  the  fact  that  in  some 
instances  the  K  I  and  salol  tests  showed  the  absence  of 
iodin  from  the  saliva,  and  of  salol  from  the  intestine.  In 
these  cases  it  was  evident  that  the  diminished  amount  of 
chyme  was  to  be  attributed  to  the  absence  of  increased 
salivary  flow,  or  to  diminished  secretion  from  the  stomach 

164 


PHYSIOLOGY  165 

mucous  membrane.  On  the  other  hand,  in  one  rotation  in 
the  supine  posture,  and  in  the  coronal  plane,  there  seemed 
to  be  a  good  deal  of  stomach  absorption,  because  the  K  I 
test  was  positive  in  26  minutes,  whereas  the  salol  test  was 
negative  just  after  the  hour's  rotation^  and  the  chyme  con- 
siderably reduced  (Siv).  Here,  evidently,  the  accretion  to 
the  stomach  contents  was  less  than  the  loss  by  absorption. 
In  these  rotations  in  the  supine  posture  there  was  no 
nausea  and  no  increased  flow  of  saliva.  It  is  evident  that 
during  the  rotations,  and  some  of  them  were  of  two  hours' 
duration,  nothing  passed  the  pylorus.  Eotation  is  all 
powerful  in  keeping  the  lower  opening  of  the  stomach 
closed.  The  rotations  in  the  upright  (sitting)  posture  had 
to  be  very  mild  in  order  that  the  test  meal  should  be  re- 
tained. Much  less  care  had  to  be  taken  in  the '  rotations 
in  the  sagittal  plane,  whilst  in  the  rotations  in  the  coronal 
plane,  with  the  subject  lying  on  the  back,  no  amount  of 
rotation  could  sicken  this  particular  subject's  stomach. 

The  firm  and  protracted  closure  of  the  pylorus  in  rota- 
tions is  to  be  explained  by  irritation  of  the  vagus  centre. 
If  the  vagus  be  divided  in  the  neck,  there  follows  loss  of 
muscle  tonus  in  the  stomach,  though  all  contractions  do 
not  disappear.  Stimulation  of  the  peripheral  stump  aug- 
ments the  vigour  of  the  contractions  of  the  muscles  of  the 
antrum  pylori,  and  causes  an  increase  of  tonus  in  the 
muscles  of  the  fundus,  as  well  as  an  increase  of  the  contrac- 
tion of  the  pyloric  and  cardiac  sphincters.  Occasionally 
stimulation  of  the  peripheral  stump  of  the  cut  vagus  may 
cause  a  primary  relaxation  or  inhibition  of  short  duration 
of  one  or  all  of  these  structures  before  the  augmentation 
tonus  begins.  A  similar  inhibition  can  be  caused  refiexly 
by  stimulation  of  the  central  stump  of  the  cut  vagus. 
This  effect  is  absent  if  the  opposite  vagus  be  divided. 
Hence,  the  vagus  has  inhibitor  and  augmentor  fibres,  and 
afferent  as  well  as  efferent  paths,  for  the  reflex  control  of 
the  gastric  musculature. 

Similarly,  it  can  be  shown  that  in  the  splanchnic  nerve 
there  are  inhibitor  and  augmentor  fibres  for  the  stomach 
muscles.  Stimulation  of  the  peripheral  end  of  the  divided 
splanchnic  causes  inhibition  of  peristalsis  and  loss  of  tone. 
The  cells  and  fibres  of  Meissner's  and  Auerbach's  plexuses 
also  act  as  a  coordinating  mechanism,,  for  the  isolated  dog's 


166  SEMICIRCULAR   CANALS 

stomach  exhibits  rh}i;hmic  movements  for  1  to  1^^  hours. 
The  cardiac  sphincter  remains  closed  normally,  partly  from 
inherent  causes,  for  the  closure  persists  for  24  hours  after 
the  severance  of  all  nerves.  This  sphincter  relaxes  at  the 
beginning  of  swallowing,  and  on  stimulation  of  the  glosso- 
pharyngeal nerve.  Whether  the  relaxation  is  due  to  inhibi- 
tion of  the  centre  maintaining  tonus,  or  to  stimulation  of 
the  inhibitory  centre,  is  a  question  that  has  not  yet  been 
satisfactorily  demonstrated.  In  the  isolated  pig's  stomach, 
the  cardiac  and  pyloric  sphincters  remain  closed  for  several 
hours. 

The  general  contractions  of  the  stomach  and  intestine 
are  therefore  inhibited  and  augmented  by  the  central 
nervous  system  through  the  splanchnic  and  vagus  nerves. 
The  chief  effect  of  stimulation  of  the  splanchnic  being 
inhibition  or  diminished  tonus,  whilst  the  chief  effect  of 
strong  vagus  stimulation  is  augmentation  of  contraction. 

Bayliss  and  Starling  '^^  consider  the  rhythmic  contrac- 
tions of  the  intestines  (including  the  stomach)  as  myo- 
genic, and  propagated  from  fibre  to  fibre,  and  that  peris- 
taltic contractions  are  reflex  in  character,  the  coordination 
being  carried  out  by  the  local  nerve  mechanisms  initiated 
by  stimulation  of  the  intestine  from  within.  Whether  this 
is  so  or  not,  the  contractions  of  the  stomach  and  intestines 
are  augmented  and  inhibited  by  the  central  nervous 
system  through  the  vagus  and  splanchnic  respectively 
(Briibaker  '^^). 

The  most  plausible  explanation  of  the  mechanism  of 
the  opening  of  the  pylorus  is  that  based  on  the  action  of 
local  coordinating  centres  stimulating  the  longitudinal 
muscle  fibres,  which,  in  the  region  of  the  pylorus,  aro 
collected  into  thickened  bands  situated  in  front  and  behind, 
and  called  the  pyloric  ligaments,  though  they  contain  no 
white  fibrous  tissue.  These  longitudinal  muscle  strands 
traverse  the  pyloric  muscle,  which  is  merely  a  thickening 
of  the  circular  elements,  and  pass  to  the  duodenum.  It  is 
assumed  that  in  contracting,  these  longitudinal  bands 
dilate  mechanically  the  circular  pyloric  ring,  being  aided 
by  reciprocal  inhibition  of  the  pyloric  circular  fibres.  It 
can  be  readily  seen  how  augmentation,  or  failure  of  inhibi- 
tion of  the  circular  coat,  could  overmaster  this  delicate 
mechanism,  and,  as  the  closed  condition  is  the  normal  one 


PHYSIOLOGY  167 

for  the  pylorus,  the  effect  of  irritation  of  the  vagus  centre 
would  be  to  keep  it  closed.  This  closed  state  of  the  pylorus 
and  the  delicate  reflex  mechanism  by  which  relaxation  oc- 
curs are  to  be  considered  as  defences  of  the  organism 
against  noxious  substances,  e.g.,  improperly  digested  food, 
etc.,  reaching  the  intestine,  where  they  might  work  seripus 
injury.  The  resistance  of  the  stomach  to  all  sorts  of  insult 
is  a  matter  of  daily  clinical  experience.  The  stomach  has, 
moreover,  in  the  chemical  constitution  of  its  specific  secre- 
tions, the  power  to  cope  with  pathogenic  organisms.  It  is 
therefore  considered  more  in  the  nature  of  a  reservoir  for 
food  rather  than  as  a  digestive  organ,  although  there  is 
too  much  tendency  at  the  present  time  to  underestimate 
the  importance  of  its  digestive  functions,  no  doubt  be- 
cause they  are  not  sufficiently  understood.  In  rotations, 
the  closure  of  the  pylorus,  or  rather  its  failure  to  relax 
and  open,  is  therefore  due  to  irritation  of  the  vagus  centre 
and  to  simultaneous  inhibition  through  the  splanchnic 
fibres.  It  may,  perhaps,  be  considered  in  the  nature  of 
a  defensive  act  on  the  part  of  the  organism,  in  part 
caused,  and  in  part  necessitated,  by  the  diminished  acidity 
that  usually  accompanies  it.  However,  closure  of  the 
pylorus  (impaired  motility)  may  be  present  without  a  de- 
ficiency of  acid,  and  frequently  occurs  in  irritated  and 
depressed  states  of  the  central  nervous  system.  Most  dys- 
pepsias, especially  those  classed  as  "nervous,"  have,  like 
rotation  sickness,  their  origin  in  fatigue-irritation  of  the 
cerebral  and  medullary  mechanisms  controlling  gastric 
motility  and  secretion.  The  only  difference  is  in  the 
degree  and  manner  of  production.  We  have  seen  that 
vomiting  in  severe  states  of  circulatory  depression  is  fre- 
quently a  potent  means  of  restoring  the  blood-supply  to  the 
medullary  centres.  The  firm  closure  of  the  pylorus,  with 
its  accompanying  nausea  and  increased  salivary  flow,  is 
but  a  step  preparatory  in  the  studied  sequence  of  nature's 
defences. 

Contractions  of  the  stomach,  intestines  and  bladder 
have  been  observed  by  Budge  and  Valentine  ^^  to  follow 
irritation  of  the  corpora  quadrigemina.  These  phenomena 
were  regarded  by  Ferrier  ^  as  one  of  the  ordinary  effects 
of  sensory  stimulation.  Cannon  ^^  has  shown  on  cats 
that,  after  bilateral  splanchnic  section,  there  is  no  change 


168  SEMICIRCULAR   CANALS 

in  the  movements  of  the  alimentary  canal,  whilst  after 
vagus  section  there  were  primar}^  twitchings  in  the  starting 
of  gastric  peristalsis,  with  marked  weakness  of  peristaltic 
contractions,  retarded  and  slow  discharge  through  the 
P3dorus,  especially  when  proteids  were  fed,  and  slow 
passage  through  the  small  intestine.  Following  combined 
section  of  the  splanchnics  and  vagi,  there  were  gastric  per- 
istaltic waves  from  the  first,  causing  deep  (normal)  con- 
striction, which  persisted  even  at  autopsy.  At  first,  as 
in  vagus  section,  there  was  retarded  discharge  through  the 
pylorus,  with  later  partial  recovery  toward  the  normal 
when  the  proteid  discharge  was  more  nearly  normal  than 
when  the  vagi  alone  were  cut.  Rhythmic  segmentation  of 
the  intestine  was  observed  in  every  condition  of  nerve 
section.  There  was  rapid  discharge  of  carbohydrate  and 
slow  discharge  of  proteid  from  the  stomach  after  vagus, 
splanchnic  and  combined  vago-splanchnic  section.  Hence 
the  differential  discharge  of  proteids  and  carbohydrates  is 
confined  to  a  local  mechanism. 

Auer,^^  working  with  rabbits,  found  on  bilateral  sec- 
tion of  the  splanchnics  that  the  stomach  showed  initial 
weak  movements  in  thirty  minutes.  Normal  peristalsis 
set  in  only  after  two  days.  The  operation  was  severe,  most 
of  the  animals  dying  in  a  few  days.  Following  sub- 
diaphragmatic section  of  both  vagi,  the  initial  signs  of 
stomach  movements  appeared  in  about  two  hours,  and 
normal  peristalsis  not  until  after  two  days. 

Rabbits  recover  well  from  this  operation,  but  are  likely 
to  develop  gastric  ulcer  at  the  pre-antral  sphincter  on  the 
lesser  curvature. 

After  combined  section  of  the  splanchnics  and  vagi,  the 
initial  peristalsis  appeared  in  less  than  thirty  minutes. 
This  peristalsis  was  slow  in  rate,  but  almost  normal  in 
strength.  Peristalsis,  normal  in  rate,  rhythm  and  strength, 
appeared  only  after  one  or  two  days,  and  then  the  gastric 
waves  tended  to  occur  in  groups.  Rabbits  usually  recover 
well  from  this  operation,  the  mortality  being  less  than  after 
splanchnic,  but  greater  than  after  vagus  section.  The 
rabbits  that  recover  have  a  greater  mortality  than  normal 
rabbits,  because  of  reduced  general  resistance.  Only  a 
slight  degree  of  reflex  inhibition  of  the  stomach  could  be 


PHYSIOLOGY  169 

got  throiigli  the  vagi,  whilst  complete  reflex  inhibition  was 
obtained  only  when  the  splanchnics  were  intact. 

After  any  section,  the  first  signs  of  peristalsis  were  seen 
in  the  pyloric  third.  The  contractions  ocpnrred  at  normal 
intervals,  but  were  weak  and  did  not  originate  in  the  mid- 
dle third  of  the  stomach.  These  first  signs  of  motility 
occurred  during,  or  at  the  end  of  the  operation,  but  normal 
peristalsis  appeared  only  much  later. 

That  the  vagus  has  some  inhibitory  fibres  had  already 
been  shown  by  Langley,^^  Meltzer,^^  ^fay,^'*  and  Cannon. ^^ 

After  section  of  the  splanchnics,  Auer  found  it  im- 
possible to  stop  gastric  movements  by  any  stimulation 
which  was  effective  when  the  splanchnics  were  intact,  with 
or  without  vagus  section. 

This  was  in  corroboration  of  Cannon  and  Murphy,^® 
who  got  inhibition  of  stomach  movements  through  the 
splanchnics. 

Auer's  experiments  furnish  no  information  for  or 
against  the  assumption  made  by  Morat,^"  that  the  splanch- 
nics have  a  motor  function. 

It  will  be  noted  that  Auer  saw  normal  stomach  peristal- 
sis only  after  one  or  two  days  following  bilateral  splanchnic 
section,  whereas  Cannon  ^^  ^  ^^  saw  no  change  from  the 
normal  movements.  Similarh',  after  combined  vago- 
splanchnic  section  Cannon  saw  normal  peristalsis  from  the 
first  in  cats,  whilst  Auer,  in  rabbits,  saw  it  only  after  one 
or  two  days.  Cannon^s  animals,  after  bilateral  vagus  sec- 
tion, were  never  so  strong  as  those  in  which  the  splanchnics 
had  been  cut.  Those  in  which  the  vagi,  or  the  splanchnics 
and  vagi,  had  been  cut,  were  asthenic.  Auer,  however, 
found  that  in  rabbits,  section  of  the  splanchnics  was  more 
severe  than  section  of  the  vagi,  or  of  the  vagi  and  splanch- 
nics. 

From  these  somewhat  conflicting  results,  it  is  evident 
that  the  vagus  carries  mainly  motor  influence  to  the  stom- 
ach, and  that  after  section  of  the  vagi  the  discharge  of  food 
through  the  pylorus  was  slow  and  retarded.  These  facts, 
however,  do  not  warrant  the  conclusion  that  stimulation  of 
the  vagus  would  necessarily  open  the  pylorus,  or  facilitate 
the  passage  of  food  into  the  duodenum.  Many  competent 
observers  have  found  gastric  inhibitory  fibres  in  the  vagus 


170  SEMICIRCULAR   CANALS 

which  may  play  an  important  part  in  the  stasis  of  food 
content  that  accompanies  rotations.  It  will  be  noted  that, 
in  spite  of  this  food  stasis,  the  gastric  musculature  was  in 
a  state  of  hyperactivity  during  the  rotations,  as  manifested 
by  frequent  eructations  the  "  lump-sensation  ^'  referred 
mainly  to  the  p3doric  region,  and  occasional  crampy  pains 
referred  mainly  to  the  cardiac  end.  Coincident  with  the 
irritation  of  the  vagus  centres  from  rotations,  there  may 
have  been  irritation  also  of  the  centres  related  to  the 
splanchnics.  As  impulses  arriving  at  the  pylorus  from 
these  sources  tend  to  counterbalance  each  other,  and  as 
normally,  the  pylorus  is  in  a  state  of  tonic  closure,  it 
would  be  expected  that  it  should  remain  closed  as  the 
result  of  rapid  rotations.  Moreover,  the  delicate  local 
mechanisms  of  the  pylorus,  which  seem  endowed  with 
almost  preternatural  powers  of  discrimination,  play  an  im- 
portant part  in  preventing  the  discharge  of  poorly  prepared 
gastric  contents  into  the  duodenum.  In  addition,  there  is 
diminished  hydrochloric  acid  content,  and  hydrochloric 
acid  is  believed  by  many  to  be  the  immediate  exciting 
stimulus  in  the  normal  reflex  opening  of  the  pylorus. 
Afferent  impulses  through  the  vagus  from  the  gastric 
mucosa  also  play  an  important  role.  To  these  we  must 
attribute  a  large  share  in  the  maintenance  of  pyloric 
closure  during  rotations.  These  afferent  vagus  impulses 
undoubtedly  are  involved  in  the  production  of  nausea, 
which,  with  closure  of  the  pylorus,  initiate  the  sequence  of 
phenomena  that  culminates  in  vomiting. 

The  segments  of  the  cord  from  which  spring  the  sixth 
to  the  ninth  thoracic  nerves  are  in  relation  with  the  stom- 
ach. It  is  from  the  cells  of  the  grey  matter,  especially  the 
central  portion,  of  these  segments  (spinal  vaso-motor 
centres),  that  the  vaso-motor  nerves  for  the  stomach  spring. 
Stimulation  of  the  gastric  branches  of  the  vagus  has  been 
observed  by  Rutherford  '^^  to  cause  congestion  of  the  gastric 
mucous  membrane,  but  Burton-Opitz  '*'*  has  shown  that  no 
vaso-motors  for  the  stomach  run  in  the  vagus.  The  un- 
doubted vascular  congestion  that  accompanies  the  later 
stages  of  rotation  sickness  seems,  therefore,  to  be  due  to 
exhaustion  of  the  vaso-motor  mechanisms,  causing  dilation 
of  the  vessels  of  the  splanchnic  area,  coupled  with  pallor 


PHYSIOLOGY  171 

and  extreme  contraction  of  the  vessels  supplying  the  sur- 
face of  the  body. 

Pawlow  ^^  has  shown  experimentally  that  secretory 
fibres  for  the  gastric  juice  are  contained  in  the  vagus.  He 
divided  the  oesophagus  in  the  neck  and  sutured  the  divided 
ends  to  the  skin,  thus  making  two  fistulous  openings. 
Later,  when  the  animal  was  fed,  the  swallowed  food  was 
discharged  through  the  upper  fistula  without  entering  the 
stomach.  Pawlow  found  that  such  a  sham  meal  caused 
an  abundant  flow  of  gastric  juice  so  long  as  the  vagi  were 
intact,  but  that  no  flow  was  observed  when  the  vagi  were 
cut.  Evidently,  therefore,  the  sensation  of  taste,  odour, 
etc.,  developed  during  mastication  and  swallowing,  set  up 
reflexly  a  stimulation  of  the  secretory  fibres  in  the  vagus. 
Pawlow  has  called  the  secretion  produced  in  this  way 
psychic  secretion,  which  implies  that  the  reflex  is  attended 
by  conscious  perception.  These  experiments  further  illus- 
trate the  close  relation  between  the  cerebral  motor  cortex 
and  gastric  function.  Psychical  secretion,  when  once 
started,  may  continue  a  long  time  after  the  initiating  stim- 
ulus (e.g.,  eating)  has  ceased.  This  is  due  to  the  fact 
that  substances  known  as  secretogogues  are  contained  in 
the  food  and  in  the  products  of  digestion.  The  action  of 
secretogogues  is  not  as  yet  completely  understood.  It  is 
known,  however,  that  they  can  produce  their  effect  after 
severance  of  all  the  nervous  connections  of  the  stomach. 
Edkins,^^  treating  the  pyloric  mucous  membrane  as  Bayliss 
and  Starling  ^^  had,  similarly  treated  the  mucous  mem- 
brane of  the  jejunum,  i.e.,  by  boiling,  extracting  with  acids, 
glycerin,  etc.,  found  that  decoctions  and  extracts  of  the 
pyloric  mucous  membrane  when  injected  into  the  blood 
caused  a  marked  secretion  of  gastric  juice,  whereas  mere 
secretogogues  injected  into  the  blood  had  no  such  effect. 
Edkins  therefore  suggests  that  secretogogues,  whether  pre- 
formed in  the  food  or  formed  during  digestion,  act  upon 
the  pyloric  mucous  membrane  and  form  a  substance  called 
gastrin,  or  gastric  secretin,  similar  to  the  corresponding 
secretin  for  pancreatic  secretion,  which  Bayliss  and  Star- 
ling ^^  had  demonstrated  as  being  formed  in  the  small 
intestine.  This  gastric  secretin,  after  absorption,  is  carried 
by  the  blood  to  the  gastric  glands  in  the  middle  third  of 


172  SEMICIRCULAR   CANALS 

the  stomach,  and  stimulate  them  to  activity  by  direct 
action.  Starling  ^^  emphasizes  the  fact  that  this  mode  of 
control  is  frequently  employed  in  the  body,  and  suggests 
the  name  hormones  (from  opiiau)^  arouse  or  excite)  for 
such  substances. 

Direct  stimulation  of  the  peripheral  end  of  the  cut 
vagus  causes  secretion  of  the  gastric  juice  only  after  a 
long,  latent  period.  The  long  latency  is  possibly  due  to 
the  presence  in  the  vagus  of  inhibitory  fibres  for  the  gastric 
glands.  These  fibres  being  simultaneously  stimulated  with 
the  secretory  fibres,  retard  the  action  of  the  latter. 

In  rotations,  the  diminished  secretion  of  gastric  juice 
depends  upon  a  perversion  or  suppression  of  all  the  activi- 
ties involved  in  the  normal  secretion.  Thus,  the  subject 
knew  he  was  going  to  be  rotated  and  made  uncomfortable, 
and  the  meal  was  not  very  appetizing  (bread  and  water). 
These  circumstances  are  very  unfavourable  for  the  psychi- 
cal secretion.  Then  the  meal  did  not  contain  preformed 
secretogogues,  as  water  and  bread  are  poor  in  these  sub- 
stances, being  in  marked  contrast  with  meat  extracts  in 
this  respect.  Moreover,  the  initial  effect  of  vagus  irrita- 
tion being  inhibition  of  secretion,  the  immediate  effect  of 
rotations  upon  the  vagus  centre  may  be  assumed  to  be  also 
inhibition  of  gastric  secretion. 

It  should  also  be  remembered  that  the  general  tendency 
of  strong  irritation  of  the  labyrinthine  receptors  is  toward 
a  sickening  of  the  stomach  with  nausea,  mental  and  physi- 
cal depression,  and  vomiting.  Such  stimulation  could 
hardly  favour  the  secretion  of  normal  gastric  juice.  The 
pylorus  is  also  in  a  state  of  spasm,  which  tends  to  prevent 
the  formation  of  gastric  secretin  by  the  action  of  whatever 
secretogogues  may  have  been  formed  in  the  progress  of 
digestion. 

Finally,  owing  to  impaired  absorption,  whatever  secre- 
tin may  have  been  formed  in  the  pyloric  or  other  portion 
of  the  mucous  membrane,  is  prevented  from  gaining  access 
to  the  glands  in  the  middle  third  of  the  stomach.  Fre- 
quently, however,  there  was  distinct  evidence  of  increased 
production  of  fluid  in  the  stomach  during  rotations.  This 
fluid  seems  to  have  been  })roduced  mainly  in  the  fundus 
of  the  stomach.  Time  and  again,  in  withdrawing  its  con- 
tents, there  was  evidence  of  constriction  separating  th^ 


PHYSIOLOGY  173 

stomach  into  two  distinct  compartments.  The  contents  of 
each  of  these  compartments  frequently  presented  a  marked 
contrast  in  appearance  and  composition.  Every  clinician 
must  have  had  similar  experience  in  washing  out  stomachs. 
Cannon,^^  and  Eoux  and  Balthazard,^^  who  studied  the 
stomach  movements  by  means  of  the  X-rays,  saw  contrac- 
tions start  in  the  middle  region  of  the  stomach  and  run- 
ning toward  the  pylorus.  It  is  possible  for  these  contrac- 
tions to  persist  as  deep  rings  seen  after  death  in  the 
excised  stomach  (Cannon  ^^).  Hence,  in  conditions  of 
extreme  disturbances  of  the  gastric  mechanisms,  such  as 
occasionally  occur  in  passing  the  stomach  tube,  more  espe- 
cially after  rotations,  it  need  not  be  wondered  at  if  deep 
constrictions  of  the  circular  bands  divide  the  stomach 
cavity  into  compartments.  Compare  the  numerous  perma- 
nent compartments  in  the  stomach  of  the  sheep,  etc.  ^^ 

Experiments  show  that  absorption  does  not  readily  take 
place  from  the  stomach.  Such  substances  as  water,  salts, 
sugar,  dextrins,  proteoses,  peptones,  alcohol,  and  other 
drugs^  may  be  absorbed,  but  not  with  the  same  facility  as 
in  the  intestine.  So  far  as  is  known,  there  are  no  such 
things  as  specific  nerve  fibres  directly  controlling  absorp- 
tion (Waymouth  Eeid^^^),  yet  in  some  of  the  rotations 
there  was  distinct  evidence  of  increased  absorption  in  in- 
stances where  the  tests  showed  absolute  stasis  of  the  stomach 
contents.  This  was  notably  the  case  in  rotations  in  dorsal 
decubitus.  However,  the  possibility  of  the  salol  not  reach- 
ing the  intestine  with  the  fluid  contents  of  the  stomach 
must  be  borne  in  mind,  as  well  as  the  possibility  that  the 
stomach  did  not  surrender  all  its  contents  through  the  tube. 

Salvioli  ^^^  found,  notwithstanding  the  dilated  condi- 
tion of  the  vessels  in  a  loop  of  dog's  gut  following  the 
administration  of  atropin,  that  the  absolute  absorption  of 
peptone  and  water  was  less  than  in  a  control  loop.  Way- 
mouth  Reid  ^^^  found  that  less  peptone  and  water  was  ab- 
sorbed when  the  mesenteric  nerves  were  stimulated;  after 
section  of  these  nerves  the  absolute  amount  of  peptone 
absorbed  was  greater,  whilst  the  absolute  amount  of  water 
absorbed  was  less  than  before  section.  The  results  follow- 
ing stimulation  of  the  mesenteric  nerves  are  attributed  by 
Reid  to  the  vaso-motor  effect.  Reid  concludes  there  are  no 
specific  nerve  fibres  for  absorption.     Techlenberg,"^*^  how- 


174  SEMICIRCULAR  CANALS 

ever,  found  marked  diminution  of  absorption  rale  for 
K  I  following  section  of  the  mesenteric  nerves.  As  this 
result  is  the  reverse  of  what  should  be  expected  with  the 
intestinal  vessels  dilated,  Tecklenberg  hints  at  the  possi- 
bility of  absorption  being  controlled  by  local  mechanisms 
in  the  plexuses  of  Auerbach  and  Meissner. 

Experiments  were  made  to  test  the  effect  of  hydrochloric 
acid  content  upon  gastric  stasis  in  the  disturbances  that 
attend  rotations.  On  two  occasions  test  meals,  consisting 
of  two  ounces  of  bread  and  seven  ounces  of  water,  con- 
taining free  HCl  .182%  by  weight,  were  given  upon  an 
empty  stomach,  and  mild  rotations  about  the  long  axis 
kept  up  continuously  for  one  hour.  The  tests  showed  no 
absorption  and  no  passage  of  food  into  the  intestines.  In 
these  cases  the  salol  was  administered  at  the  beginning  of 
the  meal,  and  in  one  case  the  subject  had  been  given  hypo- 
dermically  strychnin  sulphate  gr  ^/go  twenty  minutes 
before  the  test  meal.  The  amounts  of  chyme  returned  after 
one  hour  were  §  xi  and  5  ix,  the  latter  being  from  the 
subject  who  had  had  the  strychnin.  The  analyses  showed 
some  interesting  facts.  The  specimen  from  the  subject 
who  had  had  strychnin  showed:  total  acidity  .153,  free 
HCl  .065,  combined  HCl  .065 ;  whilst  that  from  the  other 
subject  showed :  total  acidity  .248,  free  HCl  .153,  combined 
HCl  .080.  In  a  control  test  meal  given  the  latter  subject, 
consisting  of  the  ordinary  Ewald  meal,  and  retained  for 
one  hour,  the  figures  were:  amount  of  chyme  ,^  iii,  total 
acidity  .233,  free  HCl  .131,  combined  HCl  .041.  As  a 
further  means  of  control,  two  ounces  of  the  bread  used  in 
the  meals  were  soaked  in  5  vii  of  water  containing  .182% 
of  HCl.  This  was  kept  at  a  temperature  of  100°  F.  for 
one  hour.  It  was  found  that  the  bread  had  absorbed  the 
whole  of  the  fluid  and  become  a  soddened  mass,  with  a 
bulk  of  nine  fluid  ounces.  Fluid  was  expressed  from  this 
mass  by  squeezing  in  plain  sterilized  gauze.  This  fluid 
was  filtered  and  analyzed,  as  usual.  The  figures  were: 
total  acidity  .138,  free  HCl  .102,  combined  HCl  .036. 
The  starches  and  proteins  had  undergone  little,  if  any, 
change.  In  the  two  test  meals  given  with  the  acid,  the 
protein  digestion  seemed  to  have  Jbeen  carried  on  well,  and 
the  tests  for  protein  enzymes  showed  that  these  bodies  were 
present  in  normal  amount.    The  digestion  of  the  starches 


PHYSIOLOGY  175 

seemed  retarded  somewhat,  however,  there  being  marked 
evidence  of  free  starch,  with  traces  of  amylodextrin,  whilst 
there  was  little  or  no  evidence  of  erythrodextrin  or 
achroodextrin.  There  was  no  maltose,  or  other  reducing 
agent  for  Fehling's  solution,  beyond  what  was  found  to 
have  already  been  present  in  the  control  mixture  of  bread 
and  acid,  both  immediately  after  mixing  and  after  being 
allowed  to  stand  at  100°  F.  for  one  hour.  The  tests  for 
starch  digestion  in  the  meals  given  with  the  acid  presented 
a  marked  contrast  when  compared  with  the  results  of  simi- 
lar test  meals  given  without  acid.  They  show  conclusively 
that  the  presence  of  acid  from  the  beginning  of  a  meal  is  a 
great  hindrance  to  the  digestion  of  carbohydrates.  The 
coagulating  enzymes  were  normal. 

These  experiments  show  that  the  presence  of  free  HCl 
in  the  stomach  is  not  sufficient  to  overcome  the  resistance 
offered  at  the  pylorus  to  the  forward  propulsion  of  food 
during  rotations.  They  also  seem  to  show  that  the  presence 
of  acid  in  the  stomach  favors  the  formation  of  peptonizing 
and  coagulating  enzymes,  perhaps  by  direct  stimulation  of 
the  gland-bearing  area.  Moreover,  because  there  was  no 
absorption,  and  because  stasis  was  complete,  the  increased 
amount  of  chyme,  §  xi,  as  compared  with  the  quantity  of 
material  ingested,  points  to  the  secretion  of  fluid  by  the 
gastric  mucous  membrane,  even  making  allowance  for 
some  increase  of  saliva  which  might  have  been  accidentally 
swallowed. 

The  fate  of  the  acid  put  into  the  stomach  seems,  to 
some  extent,  a  problem.  In  the  case  where  the  free  HCl 
was  so  much  reduced,  the  amount  of  the  chyme  was  §  ix, 
which  was  exactly  the  bulk  represented  by  the  meal  in- 
gested. Making  allowance  for  the  saliva  swallowed  with 
the  meal,  and  perhaps  for  some  shreds  and  detritus  from 
the  gastric  mucous  membrane,  the  quantitative  figures 
nearly  resemble  those  from  the  control  mixture  of  bread 
and  acidulated  water.  It  may  be  noted  that  this  subject 
never  forms  free  HCl  in  rotation  tests,  and  the  evidence 
indicated  that  he  did  not  do  so  here.  It  is  interesting  to 
note,  however,  that  his  coagulating  and  peptonizing 
enzymes  were  normal  here,  though  on  several  other  occa- 
sions they  were  found  diminished  or  absent  in  rotation 
tests.     There  may,  however,  have  been  some  gastric  juice 


176  SEMICIRCULAR   CANALS 

in  the  stomach  before  the  test  meal  was  given  On  this  occa- 
sion, as  the  stomach  was  in  the  resting  state,  i.e.,  fasting,  in 
the  early  morning.  This,  however,  is  not  at  all  probable, 
as  on  numerons  occasions  the  stomach  contents,  when  re- 
moved, whilst  the  subject  was  fasting  in  the  early  morning, 
showed  little  or  no  evidence  of  free  HCl. 

In  the  other  subject  there  was  an  increase  of  free  HCl 
as  compared  with  the  figures  obtained  from  the  control 
mixture  of  bread  and  acidulated  water.  This  is  explained 
by  the  fact  that  with  this  subject,  even  in  severe  rotations, 
the  tests  always  show  the  presence  of  free  HCl  though  this 
is  always  diminished  in  amount,  generally  about  .09%  to 
.10%.  Making  allowance  for  dilution  by  saliva  and  by 
gastric  secretion,  this  amount,  added  to  that  obtained  from 
the  artificial  meal  (bread  and  acid  mixture),  would  bring 
the  figure  near  that  obtained  from  the  test  meal  with  the 
acid. 

Another  effect  of  rotation  upon  the  stomach  was  fail- 
ure of  absorption,  which  occurred  frequently,  even  when 
the  salivary  flow  was  intense.  Diminished  acidity  was  a 
constant  feature,  and  was  present  with  diminished,  as  well 
as  with  increased,  saliva.  Hence,  the  production  of  stom- 
ach acid  was  retarded.  With  this,  there  was  found  at  times 
absence  or  diminution  of  the  peptonizing  enzyme  (pepsin), 
and  even  of  its  zymogen  (pepsinogen).  Less  frequently 
there  was  also  diminution  of  the  coagulating  enzyme 
(rennet,  chymosin),  and  very  rarely  of  its  zymogen 
(chymosinogen).  The  tests  were  numerous  and  were  care- 
fully repeated  whenever  the  enzymes  were  found  to  be 
abnormal.  In  this  way  many  apparent  abnormalities  were 
ruled  out.  Nevertheless,  the  facts  as  above  stated  were 
found  to  obtain.  Similarl}'',  in  the  tests  for  absorption, 
where  the  reaction  for  iodin  in  the  saliva  proved  positive, 
the  greatest  care  was  subsequently  observed  so  as  to  elimi- 
nate the  possibility  of  error.  As  to  the  excretion  or  secre- 
tion of  liquids  into  the  stomach  cavity  by  its  mucous 
membrane,  the  conclusion  is  that  such  a  thing  occurs 
during  rotations.  The  increased  chyme,  however,  always 
seemed  to  bear  some  direct  relation  to  the  increased  saliva. 
The  low  acidity  and  the  diminished  ferment  action,  as  well 
as  the  nljscnce  of  excessive  amounts  of  mucus,  seem  to 
strengthen  this  view.    Moreover,  from  time  to  time  during 


PHYSIOLOGY  177 

the  rotation  experiments,  fairly  positive  proof  was  exhib- 
ited of  congestion  of  the  stomach,  as  evidenced  by  hsemate- 
mesis,  both  spontaneous  and  on  attempting  to  wash  out 
the  stomach.  Care  was  taken  to  eliminate  cases  in  which 
the  hemorrhage  might  possibly  be  attributed  to  the  stom- 
ach tube.  The  congestion  of  the  abdominal  viscera  harmo- 
nizes with  what  is  known  to  occur  on  failure  of  the  general 
circulation  due  to  vaso-dilatation  of  the  splanchnic  area. 
Similar  evidence  of  gastric  congestion  was  apparent,  both 
in  aural  irrigations  and  in  conditions  of  sea-sickness. 
Finally,  vomiting  of  the  projectile  type  forms  the  climax 
of  the  stomach  disturbances  associated  with  rotation 
sickness. 

A  rational  interpretation  of  the  phenomena  of  nausea 
and  vomiting,  as  observed  in  rotation  sickness  and  other 
disorders,  seems  impossible  unless  the  existence  of  a  vom- 
iting centre  or  of  some  similar  mechanism  be  assumed. 
The  exact  location  of  such  a  centre  may  be  disregarded,  as 
for  present  purposes  it  is  immaterial  whether  it  be  confined 
to  the  medulla,  cerebellum  or  mid-brain.  Such  a  centre 
would  naturally  have  the  most  widespread  relations  with 
the  various  receptive  areas  in  different  parts  of  the  body. 
The  relations  would,  of  course,  be  more  intimate  with 
certain  receptor  fields,  e.g.,  the  fields  of  distribution  of 
the  senory  vagus  arcs,  and  of  the  labyrinthine  and  olfactory 
nerves.  The  relation  with  the  cerebellum  may  be  only 
an  indirect  one,  the  nausea  and  vomiting  incidental  to 
cerebellar  disease  being  the  result  of  disturbances  created 
in  the  cerebello-cerebral  and  cerebro-medullary  (efferent) 
circuits.  In  other  words,  the  nausea  and  vomiting  in  cere- 
bellar disease  may  result  from  the  vertigo  incidental  to 
cerebellar  disturbances.  The  same  is  probably  true  for  the 
nausea  and  vomiting  that  follow  disturbances  of  the  semi- 
circular canals,  whilst  there  is  reason  for  believing  that 
the  otolithic  apparatus  of  the  vestibule  is  mainly  in  direct 
relation  with  the  nausea  and  vomiting  mechanism.  The 
fact  that  so  many  afferent  paths  play  upon  a  single  motor 
mechanism  affords  abundant  opportunity  for  mutual  re- 
enforcement  (bahnimg)  of  impulses  arriving  at  the  com- 
mon centre  by  allied  arcs  from  various  receptive  areas. 
The  lowering  of  the  threshold  at  the  final  common  path 
through  irritation  in  one  receptive  field  may  abnormally 


178  SEMICIRCULAR   CANALS 

enhance  the  value  of  stimuli  acting  in  other  receptive  areas. 
Thus^  in  rotation  sickness,  when  gastric  function  has  been 
seriously  disordered  and  nausea  has  become  established,  the 
presence  of  food  or  mucus  in  the  stomach  becomes  an 
important  secondary  source  of  distress  until  relieved  by 
vomiting.  It  is  probable  that  the  nausea  caused  by  mor- 
phin  is  produced  by  the  effect  of  the  drug,  or  of  its  oxida- 
tion products,  upon  the  gastric  receptors  partly,  and  partly 
upon  the  nausea  and  vomiting  centre.  The  well-known 
disagreeable  subjective  complex  variously  termed  "nausea," 
"the  feeling  of  nausea,"  etc.,  has  its  immediate  origin  in 
the  cerebral  cortex,  and  is  the  psychic  equivalent  of  the 
motor  disturbances  originating  in  the  vomiting  centre. 

It  should  be  mentioned  that,  although  the  fibre  con- 
nections between  the  olfactory  paths  and  the  medullary 
nuclei  have  not  been  completely  traced,  it  is  highly  prob- 
able that  such  connections  exist  by  way  of  the  cortico- 
mammillary  tract  from  the  uncus  and  hippocampus  to 
the  mammillary  nucleus,  and  thence,  (1)  by  way  of  the 
mammillo-tegmental  tracts  proper  to  the  tegmentum  of 
the  mid-brain,  and  possibly  to  lower  levels;  (2)  by  fibres 
of  the  pedunculus  corporis  mammillaris  to  the  tegmentum, 
which  Kolliker,  however,  believes  end  in  the  grey  matter 
about  the  aqueduct  of  Sylvius,  near  the  origin  of  the  fourth 
nerve;  (3)  possibly  by  fibres  to  the  posterior  longitudinal 
fasciculus  via  the  hypothalamic  commissure.  Another  and 
more  direct  path  for  impulses  from  the  olfactory  receptors 
in  the  nasal  membrane  lies  by  way  of  fibres  in  tlie  strand 
from  the  cortex  of  the  olfactory  bulb  to  the  thalamus, 
thence  by  way  of  the  thalamo-mammillary  fibres  to  the 
mammillary  nucleus,  and  thence  by  way  of  the  mammillo- 
tegmental  tracts  to  the  tegmentum  and  lower  levels.  For 
reasons  often  repeated,  it  does  not  seem  correct  to  attribute 
to  any  single  cranial  or  spinal  nerve  nucleus  the  coordina- 
tion that  is  necessitated  by  a  combination  of  acts  involving 
widely  separated  structures.  Each  nucleus,  it  may  be 
admitted,  has  its  coordinating  functions  proper  to  itself, 
and  also  acts  subordinatcly  to  a  higher  coordinating  power, 
which,  by  means  of  its  manifold  connections  with  the 
various  lower  and  higher  levels,  brings  about  the  harmony 
of  associated  action.  In  fishes  there  is  reason  to  believe 
that  the  mesencephalon  is  in  intimate  relation  with  the 


PHYSIOLOGY  179 

lab}Tinths  and  with  the  mechanisms  of  nansea  and  Tom- 
iting.  In  the  higher  forms,  with  the  greater  development 
of  the  cerebrum  and  cerebellum,  accompanied,  in  some 
instances,  with  recession  of  the  olfactory  organs,  newer  re- 
lations have  been  superadded  by  which  cerebellar  and  spon- 
taneous psychic  impressions  exert  a  profound  influence  over 
the  motor  neurones  directly  concerned  in  nausea  and  vom- 
iting. Lab}Tinthine  impressions  are  so  intimately  asso- 
ciated with  cerebellar  function  that  whatever  influence  they 
have  in  the  causation  of  nausea  and  vomiting  must  come, 
it  seems,  mainly  by  way  of  the  cerebellum,  for  disturbances 
of  equilibrium  always  precede  nausea  and  vomiting  in  rota- 
tion sickness.  ZSTevertheless,  it  is  probable  that  the  otolithic 
apparatus  is  directly  related  to  the  vomiting  mechanism. 
Similarly,  retinal  impressions  which,  in  the  higher  forms, 
are  so  bound  up  with  cerebral  development  and  psychic 
function,  affect  the  vomiting  mechanism,  for  the  most  part, 
indirectly  through  the  cerebello-cerebral  and  cerebro- 
medullary  circuits,  as  well  as  through  sensory  psychic 
pathways. 

The  perversion  of  the  sense  of  smell,  as  evidenced  by  the 
painfully  disagreeable  odour  of  tobacco-smoke,  is  another 
instance  of  "bahnung,"  i.e.,  reenforcement  through  allied 
reflexes  having  reflex  arcs,  which,  though  beginning  in 
receptor  organs  of  different  species,  are  nevertheless  allied 
arcs  and  act  harmoniously  on  the  same  common  path.  The 
absence  of  vomiting,  or  the  lessened  tendency  to  it  ob- 
served whilst  the  subject  was  in  the  recumbent  posture, 
and  more  especially  seen  in  dorsal  decubitus,  may  be 
accounted  for  not  only  by  the  lessened  demands  made  on 
the  neuro-vascular  mechanisms  and  the  greater  ease  with 
which  the  medullary  and  cerebral  circulation  is  main- 
tained in  recumbency,  but  also  to  a  great  extent  by  the 
absence  of  efforts  at  balancing.  These  factors  combined, 
reduced  the  disturbances  consequent  upon  labyrinthine 
irritation  to  a  minimum.  The  lab}Tinthine  receptors  are 
acted  upon  during  rotations  in  recumbency  just  as  effl- 
ciently  as  in  rotations  with  the  subject  in  the  erect  posture. 
The  impulses  generated  in  them  are  transmitted  centrally 
along  the  afferent  arcs,  but  they  are  incapable  of  exciting 
the  neurones  of  the  final  common  path  to  reflex  activity, 
i.e.,  the  threshold  at  the  commencement  of  the  final  com- 


180  SEMICIRCULAR  CANALS 

moil  path  is  too  high  so  long  as  the  subject  is  in  recumbency. 
^Yhen,  however,  he  attempts  to  stand  up,  there  is  a  ten- 
dency to  medulhiry  anaemia,  and  the  demand  made  upon 
the  neuro-vascular  system  by  the  erect  posture,  coupled 
with  efforts  at  balancing  under  the  influence  of  unusual 
and  irregular  excitations  in  the  labyrinthine  receptors, 
causes  a  mutual  reenforcement  ("bahnung")  between  the 
various  afferent  arcs,  with  a  lowering  of  the  threshold  at 
the  commencement  of  the  final  common  path.  If  the  stim- 
ulation of  the  labyrinthine  receptors  be  of  mild  degree, 
only  moderate  reactions  are  evoked  in  the  motor  neurones 
of  the  final  common  path,  or  perhaps  only  a  part  of  the 
neurones  of  the  final  common  path  are  involved,  causing 
slight  nausea,  salivation,  mild  contractions  of  the  stomach 
musculature,  the  sensation  of  "lump"  in  the  stomach,  or 
of  "lump  in  the  throat."  The  latter  sensation  is  due  prob- 
ably to  abnormal  irritability,  or  perhaps  irregular  mus- 
cular contractions  in  the  upper  part  of  the  oesophagus,  as 
evidenced  by  the  frequent  voluntary  attempts  at  swallowing 
made  by  the  subject  to  overcome  the  "feeling"  and  ward 
off  the  oncoming  sickness.  The  "lump-sensation"  in  the 
stomach  is  probably  due  to  contraction  of  the  fundic  or 
pyloric  musculature.  Where  the  stimulus  can  be  graded, 
various  degrees  of  reaction  may  be  obtained,  from  slight 
disagreeable  sensations  to  the  utmost  degree  of  distress, 
which  reaches  its  climax  just  before  vomiting. 

The  frequent  eructations  that  occur  in  rotation  sickness 
are  the  result  of  contraction  of  the  gastric  musculature, 
coupled  with  relaxation  of  the  normal  tonic  contraction  of 
the  cardiac  sphincter.  The  diminished  acidity  favors  eruc- 
tations, since  Cannon  ^^  has  shown  that  in  animals  regurgi- 
tation readily  takes  place  from  a  stomach  filled  with  neutral 
fluid,  whereas  if  the  fluid  be  brought  to  the  degree  of 
normal  acidity,  no  regurgitation  takes  place.  The  effect 
of  the  acid  in  preventing  regurgitation  is  seen  when  both 
vagi  have  been  cut.  Hence,  it  is  to  be  attributed  to  local 
mechanisms. 

Rotation  sickness  was  much  more  readily  induced  in 
June  than  in  January  and  February.  Thus,  in  June  a 
few  mild  turns  of  the  chair  brought  the  subject  to  the 
verge  of  vomiting,  whereas  in  the  colder  months,  repeated 
brisk  rotations  could  be  withstood  by  the  same  subject  for 


PHYSIOLOGY  181 

quite  some  time  before  the  onset  of  nausea.  The  explana- 
tion of  this  fact  rests  on  the  general  tonic  effects  of  cold 
upon  the  vaso-motor  mechanisms,  whereby  the  general  and 
medullary  circulation  was  well  maintained  and  the  dis- 
orders of  equilibration  consequent  upon  unusual  or  irreg- 
ular stimulation  of  the  labyrinthine  receptors  were  readily 
compensated.  In  direct  contrast  with  these  are  the  general 
relaxing  effects  of  the  summer  warmth.  The  direct  effect 
of  cold  upon  the  labyrinthine  receptors  should  also  be 
borne  in  mind.  It  is  possible,  judging  from  the  effects  of 
aural  irrigations,  and  from  certain  clinical  observations, 
that  in  cold  weather  the  functional  activity  of  the  labyrin- 
thine receptors  is  depressed,  i.e.,  that  the  threshold  for 
stimuli  is  raised  in  them. 

During  rotations  in  various  planes  there  frequently  oc- 
curred a  sense  of  uneasiness  in  the  bowels,  with  occasional 
passage  of  flatus.  In  susceptible  subjects,  after  severe  rota- 
tions, there  w^ere  general  tremulousness  and  muscular 
weakness,  which  persisted  in  some  instances  for  hours  after 
the  rotations,  especially  in  those  cases  in  which  vomiting 
did  not  occur,  and  the  stomach  was  not  otherwise  relieved 
of  its  contents. 

The  conclusions  are: 

1.  That  rotation  profoundly  affects  the  stomach,  and 
presumably  also  the   intestinal   functions,   as   manifested, 

(a)  by  persistent  closure  of  the  pylorus,  with  stasis  of  the 
stomach  contents  and  relaxation  of  the  cardiac  sphincter; 

(b)  by  congestion  of  the  gastric  mucous  membrane,  with 
diminished  absorption;  (c)  by  impaired  secretion  of  gas- 
tric juice,  with  relative  and  absolute  diminution  of  the 
specific  acid  and  enzymes;  (d)  by  nausea  and  increased 
salivary  flow;  (e)  by  general  distress  and  wretchedness,  re- 
ferred especially  to  the  stomach;  (f)  by  eructations, 
passage  of  flatus,  etc.,  and  vomiting. 

2.  That  these  disturbances  are  initiated  primarily  by 
irritation  and  irregular  stimulation  of  the  labyrinthine 
receptors,  which  in  turn  affect  the  nausea  and  vomiting 
mechanism  (vomiting  centre),  directly,  perhaps,  in  the 
case  of  the  receptors  in  the  maculae  of  the  vestibule,  and 
indirectly  via  the  cerebello-cerebral  and  the  cerebral-effer- 
ent circuits  in  the  case  of  the  receptors  in  the  semicircular 
canals. 


182  SEMICIRCULAR   CANALS 

3.  That  when  rotation  sickness  has  been  induced,  the 
presence  of  food,  mucus,  or  other  material  in  the  stomach 
becomes  a  distinct  source  of  secondary  irritation,  and  tends 
to  maintain  and  aggravate  the  condition  until  relieved  by 
vomiting. 

•Jr.  That  nausea,  subjectively  considered,  is  the  psychic 
equivalent  of  a  minor  degree  of  disturbance  in  the  vomiting 
centre. 

5.  That  gastric,  olfactory,  visual,  and  other  impres- 
sions, with  their  psychic  associations  or  equivalents,  if  of 
sufficient  intensity  may,  of  themselves,  under  ordinary  con- 
ditions, initiate  the  phenomena  of  nausea  and  vomiting, 
whilst  under  conditions  of  increased  irritability  of  the  vom- 
iting centre,  from  whatever  cause,  impressions  from  any 
of  these  receptor  areas,  though  of  ordinary  intensity,  may 
evoke  nausea  and  even  vomiting. 

6.  That  the  majority  of  gastric  disturbances  with  their 
well-known  associated  sensory  phenomena  have  their 
origin,  primarily  at  least,  in  a  weak  and  hyper-irritable 
condition  amounting  to  a  local  neurasthenia  of  the  nervous 
mechanisms,  especially  those  springing  from  the  cerebral 
cortex  which  control  gastric  secretion  and  motility. 


CHAPTER  XII 

THE  EFFECT  OF  DRUGS  AND  OTHER  MEASURES 
UPON  DERANGEMENTS  OF  THE  ALIMENTARY 
SYSTEM   CAUSED   BY   ROTATION    SICKNESS 

The  following  methods  were  tested  in  order  to  deter- 
mine their  effect  in  preventing  rotation  sickness,  and 
especially  the  gastric  and  intestinal  disorders  attending  it. 
The  effect  of  posture  was  tried  by  rotating  the  subject  in 
various  planes  and  noting  the  result  upon  the  subject's 
general  condition,  but  more  especially  upon  the  gastric 
motor  and  digestive  functions.  For  the  latter  purpose 
numerous  test  meals  were  given  upon  an  empty  stomach 
and  retained  for  one  or  two  hours,  during  which  the  subject 
was  rotated  constantly.  With  the  subject  sitting  upright, 
the  rotations  about  the  long  axis  had  to  be  very  mild,  as 
these  rotations  readily  induced  vomiting.  Eotations  in 
recumbency  were  borne  much  better,  especially  those  in 
the  coronal  plane,  with  the  subject  in  dorsal  decubitus. 
Eotations  in  the  sagittal  plane,  "face  forward,"  with  the 
subject  lying  upon  the  side,  were  also  well  borne,  but  rota- 
tions in  the  sagittal  plane,  "occiput  first,''  were  almost  as 
potent  in  causing  subjective  distress  and  gastric  disturb- 
ances as  rotations  about  the  long  axis  with  the  subject 
sitting  upright. 

The  effect  of  h^-pnotic  suggestion  was  next  tried.  Owing 
to  the  exaggerated  claims  made  by  enthusiasts  on  behalf 
of  hypnotism  as  a  curative  agent  in  all  sorts  of  conditions, 
including  seasickness,  gastric  disorders,  and  even  organic 
disease,  this  part  of  the  subject  seems  of  sufficient  impor- 
tance to  warrant  a  somewhat  free  transcription  of  the  notes 
made  during  the  progress  of  the  experiments. 

The  subject,  a  youth  of  19,  was  a  fairly  normal  indi- 
vidual, with  normal  ear  functions.  Six  swings  were  given 
him  in  the  sitting  posture  about  the  long  axis  of  the  body. 

183 


184  SEMICIRCULAR   CANALS 

The  characteristic  after-nystagmus,  with  its  attendant  phe- 
nomena, were  observed.  There  was  dizziness,  nausea,  in- 
clination of  the  head,  deviation  in  walking,  etc. 

The  subject  was  then  put  into  the  hypnotic  state  and 
placed  in  the  swing.  No  suggestion  was  made  to  him. 
With  a  swing  from  left  to  right,  the  subject  had  to  be  sup- 
ported to  prevent  him  falling  from  the  swing.  After  the 
swing,  he  could  neither  balance  well  nor  walk  steadily. 
Immediately  he  was  taken  out  of  the  hypnotic  state,  and 
he  said  he  felt  wretched  and  "sick  at  his  stomach.'^  There 
was  no  vomiting.  Under  hypnosis,  the  suggestion  was  now 
made  to  him  that  his  stomach  sickness  Avould  disappear, 
and  at  once  he  said  it  was  "all  gone  now."  On  being  taken 
out  of  the  hypnotic  state,  his  stomach  appeared  to  be  all 
right.  He  had  no  sickness  referable  to  that  organ,  but 
he  had  a  headache.  LTnder  hypnosis  it  was  suggested  that 
his  headache  would  disappear,  which  it  did  immediately. 
With  the  subject  under  "waking"  hypnosis,  it  was  sug- 
gested that  the  swing  could  not  sicken  him  or  make  him 
dizzy.  A  hard  swing  was  then  given.  Little  dizziness  was 
felt,  and  on  being  taken  from  the  swing  he  stood  and 
walked  fairly  well,  but  with  studied  effort  and  cautiously. 
He  was  able  to  stand  fairly  well  on  either  foot,  with  closed 
eyes.  This  observation  tends  to  confirm  that  of  Beard. ^^ 
The  rotations  in  Beard's  experiments,  however,  were  of  a 
very  mild  type.  The  subject  now  felt  slightly  sick  at  the 
stomach,  and  the  saliva  was  flowing  freely.  The  knee- 
jerks  were  normal.  The  head  felt  a  little  heavy.  During 
a  rest,  and  whilst  still  under  hypnosis,  it  was  found  that 
no  suggestion  of  darkness  or  of  a  strong  light  would  alter 
the  size  of  his  pupils. 

Still  under  hypnosis,  an  attempt  was  made  to  introduce 
the  stomach  tube,  but  no  amount  of  suggestion  could  over- 
come the  rebellious  pharyngeal  reflexes.  It  was  then  sug- 
gested to  him  that  he  was  sick  and  about  to  vomit,  and 
at  once  he  vomited.  Later  he  was  made  to  balance  on  one 
foot,  and  whilst  in  this  attitude  it  was  suggested  that  he 
was  unable  to  put  the  other  foot  to  the  floor.  As  he 
grew  tired,  desperate  efforts  at  balancing  were  made,  but 
the  other  foot  was  not  put  down.  Finally,  the  effect  of 
the  suggestion  was  overpowered  and  the  subject  put  down 


PHYSIOLOGY  185 

his  foot  and  walked  over  to  the  middle  of  the  room  to 
expectorate. 

At  9 :30  a.  m.  an  Ewald  breakfast  was  given.  At  9 :35, 
after  a  rotation  about  the  long  axis,  the  nsnal  nystagmus 
was  presented. 

During  a  swing  from  left  to  right  about  the  long  axis, 
it  was  noted  that  no  amount  of  suggestion  could  ward  off 
the  bad  feeling.  Instinctively  the  subject  tried  to  lie  down. 
After  a  swing  in  the  coronal  plane,  with  the  subject  in  dorsal 
decubitus,  the  typical  nystagmus  was  observed.  The  sub- 
ject put  his  hands  to  the  epigastric  region  as  if  suffering 
from  stomach  distress.  He  stated  he  felt  sick  in  his  stom- 
ach and  head.  He  also  had  headache  and  his  saliva  was 
flowing  freely.  His  skin  felt  cold,  and  he  complained  of 
chilliness  and  headache.  The  operator  laid  his  hand  upon 
the  subject's  forehead  and  assured  him  that  his  headache 
would  disappear,  which  it  did  at  once.  There  were  frequent 
eructations  at  various  times.  The  subject  manifested  a 
great  tendency  to  lie  down  and  go  to  sleep.  He  was  allowed 
to  sleep  a  short  time,  and  on  waking  he  shivered  as  with 
cold  and  complained  of  headache. 

At  10:35  the  stomach  contents  were  removed,  mainly 
by  vomiting.  The  amount  returned  was  §  xii.  Analysis 
showed  a  marked  diminution  of  enzymes  and  of  free  HCl. 
'No  absorption  or  motility  tests  were  made,  but  the  indica- 
tions were  those  of  complete  stasis  and  diminished  absorp- 
tion. Before  taking  him  out  of  the  hypnotic  state  it  was 
suggested  that  his  memory  of  all  the  disagreeable  incidents 
of  the  morning  would  be  blank,  and  that  he  would  feel 
well  and  suffer  no  discomforting  after-effects.  On  coming 
out  of  hypnosis,  the  subject  said :  "  It's  cold.  There's 
something  in  my  mouth  that  smells."  Afterward  he  told 
me  that  his  only  recollection  of  what  had  happened  was 
that  he  had  been  dizzy  and  had  felt  a  choking  in  his 
throat.  The  dizziness  was  a  memory  from  the  swing, 
whilst  the  choking  was  due  to  the  attempts  made  to  intro- 
duce the  stomach  tube.  Some  time  afterward  the  subject 
said  that  he  felt  the  effects  of  the  rotation  sickness  for  a 
whole  week.  No  amount  of  persuasion  could  induce  him 
to  permit  a  repetition  of  the  experiments,  though  he  sub- 
mitted  to   numerous   irrigation   tests.      AH   through   the 


186  SEMICIRCULAR   CANALS 

swings,  given  with  the  test  meal  in  the  stomach,  it  was 
constantly  suggested  to  the  subject  that  the  swing  could 
not  make  him  dizzy  or  sick  in  any  way. 

iSText  was  studied  the  effect  of  extracts  made  from  vari- 
ous portions  of  the  mucous  membrane  of  the  stomach  and 
intestines,  after  the  manner  followed  by  Bayliss  and  Star- 
ling,^^  and  by  Edkins.^^  As  these  experiments  belong  to 
an  independent  series,  the  full  details  are  reported  else- 
where. The  results  showed  however,  that  in  rotation 
sickness  these  extracts  favoured  the  production  of  free  HCl 
and  digestive  enzymes  and  aided  absorption  and  motility, 
both  in  the  stomach  and  intestines. 

Finally,  various  drugs  were  tested,  some  singly  and 
some  both  singly  and  in  different  combinations.  The  fol- 
lowing were  tried:  atropin  crystals  gr  V45  hypodermat- 
ically,  ditto  per  os;  hyoscyamin  gr  ^/go  hypodermatically ; 
orthoform  gr  v.  per  os;  hyoscin  hydrobromid  gr  Vjoo 
h}"podermatically ;  atropin  sulphate  gr  Vioo  P^^  os;  co- 
cain  hydrochlorid  gr  V4  per  os;  atropin  sulphate  gr 
^/75 ,  and  strychnin  nitrate  gr  '^/^^  in  combination  hypo- 
dermatically. The  drugs  were  tested  by  rotating  the  sub- 
ject in  various  planes  and  postures  when  a.  reasonable  time 
had  elapsed  after  their  administration,  and  observing  the 
controlling  effects,  if  any,  upon  the  sickness.  With  some 
of  the  drugs,  test  meals  and  controls  were  given.  The 
test  meals  were  retained  for  one,  in  some  instances  two, 
hours.  During  this  period  the  subject  was  constantly 
rotated  in  various  planes  and  postures. 

Of  the  drugs  experimented  with,  none  was  found  to 
have  any  appreciable  effect  in  relaxing  the  pylorus.  In 
this  respect,  supine  recumbency  seemed  to  have  the  most 
potency,  especially  when  used  in  conjunction  with  atropin 
and  strychnin  hypodermatically.  In  the  rotations  about 
the  long  axis,  with  the  subject  sitting  upright,  atropin 
and  strychnin  had  no  effect  in  relaxing  the  pylorus.  After 
atropin,  the  amount  of  chyme  was  considerably  increased. 
In  two  out  of  three  trials  the  K  I  test  for  absorption  was 
positive.  In  one  case  the  saliva  was  diminished  distinctly, 
and  in  the  other  two  there  was  no  increased  salivation. 
Moreover,  nausea  was  very  slight  or  absent  in  all  three 
trials.  We  are  therefore  driven  to  the  conclusion,  since  the 
test  for  salol  in  the  intestine  was  negative,  that  secretion 


PHYSIOLOGY  187 

or  transudation  was  responsible  for  the  increased  chyme. 
With  strychnin  and  atropin  combined,  and  with  the  sub- 
ject in  the  supine  posture  and  rotated  in  the  coronal  plane, 
there  was  active  absorption  from  the  stomach,  the  K  I  test 
reacting  for  iodin  in  the  saliva  in  26  minutes,  whilst  the 
test  for  salol  in  the  intestines  was  negative,  and  at  the 
same  time  the  chyme  was  reduced  in  amount  and  of  a  less 
fluid  consistency  than  usual.  Eecumbency  and  the  plane 
of  the  rotation  were  the  chief  factors  here,  whilst  the 
atropin  and  strychnin  acted  as  adjuvants.  The  atropin 
and  strychnin  had  their  usual  happy  effect  in  preventing 
the  general  discomfort  of  the  subject.  Xeither  cocain  nor 
orthoform  per  os  was  found  to  aid  absorption  or  motility, 
nor  was  either  drug  of  benefit  in  preventing  dizziness, 
nausea,  excess  of  saliva,  or  other  discomfort.  Hyoscin  was 
ineffective  against  dizziness,  nausea,  etc.,  and  caused  so 
much  psychic  and  motor  depression  that  the  subject  had 
to  be  taken  home  and  put  to  bed.  There  were  no  danger 
signals,  however,  the  chief  symptom  being  an  uncon- 
trollable tendency  to  sleep. 

The  following  figures  represent  the  averages  taken  from 
analyses  made  after  Ewald  test  meals  retained  during  rota- 
tions. The  general  effect  of  rotation  sickness  upon  the 
acid  content  was  as  follows:  The  average  taken  from  two 
Ewald  breakfasts,  which  were  retained  one  hour  under  nor- 
mal conditions  without  rotations,  was:  total  acidity  30%, 
free  HCl    .19%,  combined  HCl    .06%. 

The  average  from  fourteen  meals,  retained  during  rota- 
tion in  various  planes,  with  the  subject  in  various  postures, 
was:  total  acidity  .17%,  free  HCl  .09%,  combined  HCl 
.06%.  The  average  in  meals  retained  during  rotations 
about  the  long  axis  was :  total  acidity  .02%,  free  HCl  .10%, 
combined  HCl  .07%.  The  average  for  four  meals  after 
rotations  in  the  coronal  plane,  with  the  subject  lying  in 
the  supine  posture,  was:  total  acidity  .17%,  free  HCl 
.08%,  combined  HCl    .06%. 

In  rotations  in  the  sagittal  plane,  with  the  subject  lying 
on  the  side,  the  average  for  three  meals  was:  total  acidity 
.12%,  free  HCl  .06%,  combined  HCl  .03%.  In  rotations 
about  the  long  axis,  with  the  subject  sitting  upright,  and 
after  the  administration  of  atropin,  the  average  for 
four   meals   was:    total   acidity   .20%,   free   HCl     .11%, 


188  SEMICIRCULAR   CANALS 

combined  HCl  .08%.  In  rotations  about  the  long 
axis,  with  the  subject  sitting  upright,  the  rotations  and 
reverses  had  to  be  of  the  mildest  kind  to  forestall  vomiting, 
whereas  in  rotations  with  the  subject  lying  down  there  was 
little  tendency  to  vomit,  even  when  the  rotations  were  brisk 
and  the  reversals  or  stoppings  rather  sudden. 

In  rotations  in  the  coronal  plane,  with  the  subject  lying 
on  the  back,  and  after  the  administration  of  atropin  and 
strychnin,  the  figures  were:  total  acidity  .18%,  free  HCl 
.07%,  combined  HCl    .08%. 

The  lowest  figures  occurred  with  rotations  in  the  sag- 
ittal plane,  including  rotations  with  ^'face  first''  and  with 
"occiput  first,''  e.g.,  total  acidity,  .07%,  free  HCl  .029%, 
combined  HCl  .029%.  The  next  lowest  were  with  rota- 
tions in  the  coronal  plane,  with  the  subject  in  hypnosis, 
and  under  the  suggestion  that  the  rotation  would  not  sicken 
him,  etc.  The  figures  were:  total  acidity  .12%,  free  HCl 
.03%,  combined  HCl  .08%.  There  was  a  trace  of  blood 
in  the  chyme. 

Rotation  in  the  coronal  plane,  with  the  subject  in  the 
prone  posture,  gave:  total  acidity  .18%,  free  HCl  .08%, 
combined  HCl   .05%. 

The  contents  from  the  resting  stomach  gave,  as  an 
average:  total  acidity  .14%,  free  HCl  .06%,  combined 
HCl  .05%. 

The  amount  of  chyme  withdrawn  after  one  hour's  re- 
tention during  rotations  was  as  follows:  Average  after 
five  meals  in  rotations  about  the  long  axis,  §  xiiss ;  after 
four  meals  in  rotations  in  the  coronal  plane,  with  the 
subject  lying  on  the  back,  ^  x ;  after  sagittal  rotations,  with 
the  subject  lying  on  the  side,  for  three  meals  the  average 
was  §  xii ;  after  rotations  about  the  long  axis,  with  the 
subject  sitting  upright,  and  after  the  administration  of 
atropin,  the  average  for  four  moals  was  %  xii.  After 
rotations  in  the  coronal  plane,  with  the  subject  lying  on 
the  back,  and  after  the  administration  of  strychnin  and 
atropin,  the  amount  for  one  meal  was  ,^  ix.  The  general 
average  for  all  the  meals  under  rotations  in  the  various 
planes  and  postures  was  ,^  x.  In  each  instance  the  meal 
consisted  of,  bread  ^  ii  and  water  ^  viii. 

The  peptic  ferments  were  found  diminished  or  absent 
in  the  three  cases  where  the  acidity  was  very  low,  viz.,  in 


PHYSIOLOGY  189 

rotations  in  the  sagittal  plane^,  in  the  coronal  plane  with 
the  subject  lying  prone,  and  in  the  coronal  plane  with  the 
subject  under  hypnosis. 

The  salivary  flow  was  markedly  increased  in  rotations 
about  the  long  axis,  with  the  subject  sitting  upright.  It 
was  increased  slightly,  or  not  at  all,  in  rotations  in  the 
sagittal  plane,  with  the  subject  lying  on  the  side.  In  rota- 
tions in  the  coronal  plane,  with  the  subject  lying  on  the 
back,  it  was  diminished  or  not  affected.  After  atropin  it 
was  always  considerably  diminished. 

Starch  digestion  seemed  to  have  been  well  carried  on 
in  every  instance,  aided,  no  doubt,  by  the  lowered  acidity 
and  increased  salivation.  The  tests  for  motility  showed 
that  in  no  instance  was  there  evidence  of  anything  having 
passed  the  pylorus. 

The  absorption  tests  showed  that  in  very  few  instances 
was  there  convincing  evidence  of  absorption  from  the  stom- 
ach. In  two  of  these  cases  the  rotation  was  in  the  coronal 
plane,  with  the  subject  lying  on  the  back,  and  in  one  of 
these  rotations  the  subject  had  had  atropin  and  strychnin. 
In  two  rotations  about  the  long  axis,  with  the  subject  sit- 
ting, upright,  and  after  the  administration  of  atropin,  the 
K  I  test  reacted  for  iodin  in  the  saliva.,  but  in  these  cases 
there  was  reason  to  believe  that  contamination  of  the  saliva 
had  taken  place  on  the  administration  of  the  K  I,  as  some 
of  the  drug  was  found  loose  in  the  box  containing  the  cap- 
sules. In  subsequent  tests  special  means  were  adopted  to 
avoid  such  an  accident.  The  remaining  tests  showed  that 
no  absorption  took  place  from  the  stomach,  and  this,  even 
allowing  for  the  diminished  salivary  secretion,  which  was 
never  extreme. 

Atropin,  especially  in  combination  with  strychnin, 
afforded  almost  complete  relief  from  stomach  discomfort, 
nausea  and  increased  salivary  flow.  Vertigo  was  present, 
however,  during  the  rotations,  but  on  cessation  of  the 
latter  it  immediately  disappeared,  and  was  not  accompanied 
by  the  usual  dolor  cerebri.  The  subject  had  not  the  usual 
fear  and  apprehension  of  the  swing.  Instead  of  appearing 
worried  and  morose,  he  was  cheerful,  talkative,  and  anxious, 
to  work.  In  a  word,  his  manner  and  bearing  gave  evidence 
of  the  usual  atropin  action  on  the  cerebral  psychic  and 
motor  areas.     Atropin  manifestly  exerts,  a  powerful  local 


190  SEMICIRCULAR   CANALS 

action  on  the  gastric  vagus  sensory  terminals.  This  local 
action,  to  the  infinite  relief  of  the  subject,  eliminates  the 
stomach  and  its  contents  as  powerful  secondary  factors  in 
maintaining  vagus  nuclear  irritation.  In  other  respects,  the 
atropin  showed  its  usual  effect  in  stimulating  the  cerebral 
(psychic  and  motor)  areas  and  the  medullary  centres.  Its 
action  on  the  latter  has  been  discussed  elsewhere. 

The  general  effect  of  atropin  per  os  was  good,  as  was 
that  of  hyoscyamin  hypodermatically.  However,  neither 
was  as  efficient  as  atropin  or  its  combination  with  strych- 
nin hypodermatically. 

Experience  with  other  drugs  in  making  the  experiments 
to  determine  their  effect  upon  the  circulation  in  rotation 
sickness  rendered  it  inadvisable  to  try  their  effect  upon  the 
digestive  apparatus.  The  results  upon  the  circulation  and 
upon  the  subject's  condition  generally  were  so  unsatis- 
factory that  nothing  good  could  be  expected  from  their 
action  upon  gastric  or  intestinal  function. 

The  conclusions  are: 

1.  That  dorsal  decubitus  is  the  most  efficient  method  of 
counteracting  the  nausea  and  distress  in  rotation  sickness. 

2.  That  atropin  and  strychnin  in  combination  favour 
dorsal  decubitus,  aiding  its  action  in  tending  to  relax  the 
pyloric  sphincter,  whilst,  without  decubitus,  these  drugs 
as  well  as  cocain  and  the  other  drugs  tried,  are  ineffectual. 

3.  That  during  rotations  in  various  planes,  and  with 
the  subject  in  various  postures,  there  is  active  secretion  or 
transudation  from  the  gastric  mucosa  into  the  stomach 
cavity,  even  when  the  system  is  under  the  influence  of 
atropin. 

4.  That  this  secretion  or  transudation  represents  a  gas- 
tric juice  of  lowered  acidity,  and  in  some  instances  of 
diminished  or  absent  enzymes. 

5.  That  the  erect  posture  has  much  to  do  with  the  in- 
duction of  nausea,  salivation,  and  vomiting,  wdiilst  the 
recumbent  posture,  and  especially  dorsal  decubitus,  pre- 
vents or  alleviates  them. 

6.  That  hypnotic  suggestion  is  not  markedly  effective 
in  offsetting  the  effects  of  rotation  sickness,  nor  in  prevent- 
ing the  usual  disturbances  in  gastric  function  and  their 
immediate  attrndants. 

7.  That  atropin,  especially  in  combination  with  strych- 


PHYSIOLOGY  191 

nin,  is  very  effective  in  combating  the  nausea,  increased 
salivation  and  vomiting,  and  the  psychical  and  mental  de- 
pression that  accompany  rotation  sickness,  and  that  it  does 
this,  (1)  by  local  action  on  the  sensory  vagus  terminals  in 
the  gastric  mucous  membrane,  thereby  preventing  secondary 
irritation  of  the  vagus  and  allied  centres,  and,  (2)  by 
stimulating  the  psychic  and  motor  areas  of  the  brain,  as 
well  as  some  of  the  medullary  centres,  e.g.,  vaso-constrictor, 
respiratory,  etc.  The  usual  potency  of  the  disturbed  laby- 
rinthine and  gastric  receptors  .is,  to  a  great  extent,  offset 
or  prevented  by  this  twofold  action  of  atropin.  The 
strychnin  acts  as  an  adjuvant  in  maintaining  the  circula- 
tory and  general  tonus. 

8.  That  atropin  per  os  and  hyoscyamin  h3^podermat- 
ically  are  effective  in  counteracting  some  of  the  effects  of 
rotation  sickness,  but  not  to  the  same  degree  as  atropin, 
or  the  combination  of  atropin  and  strychnin,  used  hypo- 
dermatically. 

9.  That  cocain  and  orthoform  per  os  are  ineffective, 
whilst  hyoscin  hypodermatically  is  not  only  ineffective, 
but  seems  to  aggravate  the  phenomena  evoked  by  rotation 
sickness. 

10.  That  certain  extracts  made  from  various  parts  of 
the  mucous  membrane  of  the  stomach  are  effective  in  rota- 
tion sickness,  and  materially  favour  absorption  and  motility 
in  the  stomach  and  intestine. 


CHAPTER  XIII 

THE   EFFECT   OF   ROTATION   UPON    EQUILIBRIUM 

In  rotations  about  the  long  axis,  with  the  subject  sit- 
ting upright,  rotation  from  right  to  left  (i.e.^  in  the  direc- 
tion opposite  to  that  of  the  hands  of  a  watch,  supposing  the 
watch  to  be  placed  on  the  floor  immediately  under  the 
iswing  and  with  its  face  looking  upward,  and  the  axis  of 
its  hands  parallel  to  the  long  axis  of  the  subject's  body), 
fcauses  the  subject's  head  to  incline  toward  the  right  shoul- 
(der.  If  the  swing  be  allowed  to  slow  down  gradually,  a 
;stage  is  reached  when  the  subject  does  not  know  to  which 
:side  his  head  tends  to  fall,  as  it  seems  equally  inclined  to 
iall  laterally  to  the  right  or  left.  This  stage,  if  the  swing 
ibe  allowed  to  slow  down  still  further,  is  soon  followed  by 
la  period  when  there  is  a  distinct  tendency  of  the  head  to 
fall  to  the  opposite,  i.e.,  to  the  left  shoulder.  In  swings 
•from  left  to  right,  similar  phenomena  occur,  but  in  this 
instance  the  initial  inclination  of  the  head  is  toward  the 
Heft  shoulder.  There  is  also  at  the  beginning  of  the  rota- 
tion some  rigidity  and  inclination  of  the  upper  part  of  the 
ll)ody  in  the  same  direction  in  which  the  head  inclines. 
iSudden  acceleration,  retardation,  or  reversal  of  the  direc- 
tion of  the  rotation,  has  a  powerful  influence  upon  these 
deviations  of  the  head,  as  well  as  upon  the  vertigo  and 
other  phenomena  attending  rotation.  If  the  eyes  of  the 
subject  be  kept  closed  and  a  brisk  rotation  performed  from 
right  to  left,  and  the  swing  allowed  to  slow  down,  the  sub- 
ject's head  will  at  first  tend  to  fall  to  the  right,  and  he  will 
feel  himself  rotating  from  right  to  left.  Very  soon,  how- 
ever, as  the  swing  slows  down,  his  head  will  not  tend  to 
fall  in  any  particular  direction,  and  the  subject  will  feel 
no  sense  of  motion  whatever.  As  the  swing  still  continues 
to  slow  down,  the  head  begins  to  incline  slightly  to  the 
left  and  the  subject  now  feels  himself  revolving  from  left 

192 


PHYSIOLOGY  19B 

to  right,  though  in  reality  he  is  still  revolving  from  right 
to  left.  At  any  time  during  such  a  period  as  that  just 
^  described  an  acceleration  of  the  rotation  will  determine 
the  head  to  fall  in  the  direction  opposite  to  that  of  the 
acceleration,  and  the  subject  will  feel  himself  rotating  in 
the  direction  in  which  he  is  actually  moving.  Similarly,  if, 
after  a  few  short,  brisk  rotations  from  right  to  left  with 
eyes  closed,  the  swing  be  suddenly  retarded  or  stopped,  the 
subject's  head  will  immediately  fall  to  the  left,  and  he 
will  feel  his  body  rotating  rapidly  from  left  to  right.  If, 
now,  the  eyes  be  immediately  opened,  the  subject  no  longer 
feels  his  body  moving,  but  external  objects  appear  to  be 
moving  rapidly  about  his  body  from  left  to  right.  By 
opening  his  eyes,  his  sense  of  motion  has  become  external- 
ized, that  is,  external  objects  now  seem  to  move,  whilst  his 
body  seems  to  be  stationary.  If  the  subject  be  taken  from 
the  swing  at  this  point  he  will  be  able  to  walk,  but  will 
tend  to  deviate  toward  the  side  to  which  his  head  inclines. 
However,  it  frequently  happens  that  in  a  moment  or  so  the 
head  may  incline  to  the  opposite  side,  and  the  subject  will 
accordingly  deviate  in  that  direction. 

Observation  of  the  displacement  of  the  head  and  upper 
part  of  the  body  in  rotations  in  the  coronal  plane,  i.e., 
about  an  antero-posterior  axis  through  the  umbilicus,  was 
beset  with  some  difficulty,  for  in  these  rotations  the  subject 
was  lying  on  the  back,  i.e.,  in  the  position  of  most  stable 
equilibrium.  Another  element  that  added  to  the  difficulty 
was  retardation  of  the  swing,  which,  of  course,  reverses  the 
direction  of  the  nystagmus,  etc.  Hence,  the  notes  taken  at 
the  time  the  experiments  were  made  show  some  irregulari- 
ties and  apparent  contradictions.  The  swings,  however,  were 
repeated  again  and  again,  with  every  possible  attention  as 
to  slowing  and  acceleration,  until  the  true  facts  were  ascer- 
tained as  nearly  as  possible.  It  may  be  said  in  general  that 
rotation  in  the  coronal  plane  in  the  direction  of  the  hands 
of  the  watch  (which  in  all  these  experiments  with  the 
subject  lying  down  is  supposed  to  be  placed  on  the  sub- 
ject's breast,  with  its  face  looking  toward  the  observer), 
causes  a  tendency  to  displacement  of  the  head  and  upper 
part  of  the  body  toward  the  right,  i.e.,  in  the  direction 
against  the  hands  of  the  watch.    Similarly,  rotation  against 


194  SEMICIRCULAR   CANALS 

the  watch  caused  a  tendency  of  the  upper  part  of  the  body 
to  "pull"  or  incline  in  the  opposite  direction. 

In  determining  these  matters,  it  was  found  that  by 
placing  the  hands  on  either  side  of  the  neck  one  could 
perceive  on  which  side  the  reflex  tonus  was  exerted  in  the 
muscles.  In  addition  to  this,  the  subject  experienced  a 
painful  sense  of  effort  in  the  opponents  on  the  opposite 
side.  This  was  due  to  relative  absence  of  labyrinthine 
tonus  in  these  muscles. 

The  author,  who  is  very  susceptible  to  the  effects  of 
rotation,  went  on  the  swing  himself  to  clear  up  this  mat- 
ter. In  addition  to  the  facts  as  stated  above,  it  was  found 
that  in  rotations  in  the  mesial  plane,  "face  front,"  little, 
if  any,  reflex  tonus  could  be  detected,  whilst  in  mesial 
rotations  with  the  "occiput  first"  there  was,  at  the  com- 
mencement of  the  rotations,  a  distinct  tonus  effect  detected 
in  the  muscles  that  pull  the  head  forward,  whilst  in  sud- 
den stopping  there  was  marked  reflex  tonus  in  the  muscles 
that  pull  the  head  backward.  The  latter  was  accompanied 
by  a  sense  of  motion  in  the  mesial  plane,  "face  first."  This 
observation,  taken  in  conjunction  with  the  phenomena 
observed  on  section  of  the  posterior  canals  in  animals, 
viz.,  falling  backward,  seems  to  show,  as  Ferrier  ^  long  ago 
pointed  out,  that  mesial  rotations  with  the  "occiput  first" 
stimulates  the  receptors  in  the  ampullaa  of  the  posterior 
canals.  The  absence  of  marked  phenomena  in  mesial  rota- 
tions, "face  first,"  seems  to  point  to  the  fact  that  in  for- 
ward movements  and  rotations  the  eyes  have  so  long  and 
so  effectively  replaced  the  related  labyrinthine  receptors, 
viz.,  those  of  tlie  superior  canal,  that  the  latter  perhaps 
have  regressed  in  function  and  irritability. 

With  the  eyes  closed  and  directed  straight  ahead,  i.e., 
in  the  sagittal  plane,  it  was  found  that  in  rotation  in  the 
coronal  plane  the  subject  felt  no  movement  but  an  up-and- 
down  motion,  as  if  the  body  "seesawed"  in  the  sagittal 
plane,  with  the  head,  however,  always  appearing  to  the 
subject  to  be  lower  than  the  feet.  The  possibility  of  lateral 
swaying  of  the  swing  should  be  remembered  in  connection 
with  the  phenomena  just  noted. 

When  the  subject  was  rotated  in  the  direction  of  the 
hands  of  the  watch,  but  with  the  eyes  closed  and  strongly 
deviated  to  the  left,  i.e.,  in  the  direction  in  which  he  was 


PHYSIOLOGY  195 

moving,  he  correctly  estimated  at  the  beginning  of  the 
rotation  the  direction  in  which  his  body  was  moving,  but 
with,  at  times,  an  added  element,  viz.,  the  sensation  that 
his  body  was  rotating  about  its  long  axis  from  left  to  right. 
The  explanation  of  this  latter  phenomenon  seems  to  rest 
upon  the  fact  that  superior  oblique  muscles  are  attached 
to  the  eyeball  behind  the  centre  of  rotation  (Fuchs^^^). 
The  consequence  is,  that  in  the  production  of  rotary 
nystagmus  with  the  watch  there  is  also  a  tendency  to  cause 
movements  of  horizontal  nystagmus,  with  the  short  ele- 
ments directed  to  the  right.  This  nystagmus,  on  account 
of  the  insertion  of  the  superior  oblique  behind  the  centre 
of  rotation  of  the  eyeball,  is  favoured  in  the  right  eye  at 
least,  by  turning  the  eyes  to  the  left.  Moreover,  it  is  the 
primary  associated  equivalent  of  rotation  about  the  long 
axis  from  left  to  right. 

In  rotations  in  the  coronal  plane  with  the  watch,  if  the 
eyes  were  kept  closed  and  strongly  turned  to  the  right,  the 
subject  felt,  soon  after  the  commencement  of  rotation  and 
on  slight  slowing  perhaps,  his  body  rotating  in  the  coronal 
plane  against  the  watch.  Here,  looking  to  the  right  in- 
hibited rotary  nystagmus  with  the  watch,  and  favoured  the 
premature  induction  of  the  natural  after-n3'stagmus,  viz., 
against  the  watch,  which  is  the  associated  equivalent  of 
rotation  in  a  similar  direction. 

Another  interesting  fact  in  rotations  in  the  coronal 
plane  with  the  watch,  and  with  the  eyes  closed  and  directed 
to  the  right,  was,  that  in  addition  to  the  sense  of  rotation 
against  the  watch  the  subject  also  was  aware,  from  light 
impressions  received  through  the  closed  eyelids,  that  things 
went  "shooting  in  front  of  him  from  the  feet  toward  the 
head'^  in  the  mesial  plane,  which,  of  course,  is  associated 
with  rotation  in  the  mesial  plane  in  the  direction  "face 
forward." 

If  brisk  rotation  be  commenced  in  the  coronal  plane 
with  the  eyes  closed  and  turned  strongly  in  the  direction 
of  the  rotation,  even  then,  whilst  the  subject  correctly  esti- 
mates the  actual  direction  of  the  rotation,  turning  the  eyes 
to  the  opposite  side  immediately  begets  a  sense  of  reversal 
of  the  motion.  Similar  phenomena  occur  with  aural  irriga- 
tions. As  already  noted,  the  turning  of  the  eyes  favoured 
the  premature  induction  of  the  natural  after-nystagmus. 


19C  SEMICIRCULAR  CANALS 

In  these  rotations  in  the  coronal  plane,  the  usual  effects 
of  acceleration  and  retardation,  as  noted  in  the  rotations 
about  the  long  axis,  are  encountered.  There  are  periods 
when  the  direction  of  the  motion  is  correctly  estimated,  and 
there  are  periods  when  no  motion  whatever  is  felt.  These 
latter  occur  in  certain  positions  of  the  eyes,  as  well  as  just 
previous  to  the  sensation  of  reversals  of  direction  which  are 
evoked  by  gradual  retardation. 

In  rotations  in  the  sagittal,  or  in  a  diagonal  plane  mid- 
way between  the  sagittal  and  the  coronal,  the  direction  in 
which  the  closed  eyes  were  turned  had  a  peculiar  effect. 
In  studying  this  particular  point,  difficulties  were  encoun- 
tered owing  to  retardation  effects.  However,  the  rotations 
were  repeated  again  and  again,  and  from  a  careful  study 
of  the  results  this  conclusion  was  reached,  viz.,  that  in  rota- 
tion in  the  sagittal  and  diagonal  planes,  with  the  subject 
lying  on  the  left  side,  turning  the  closed  eyes  strongly  to 
the  right  or  left,  had  a  strong  determining  influence  on  the 
subject's  judgment  as  to  the  direction  in  which  his  body 
actually  moved  or  seemed  to  move,  so  that  if  the  objective 
determining  influence  were  only  of  slight  degree,  whether 
this  were  in  the  form  of  active  acceleration  or  reactionary 
retardation,  the  voluntary  straining  of  the  eyes  toward  the 
right  or  left  determined  the  sensation  of  motion  in  the 
direction  of  "occiput  first"  or  "face  first,"  respectively,  or 
enhanced  the  action  of  the  objective  influences  tending  to 
show  their  effects  by  causing  a  feeling  of  rotation  in  either 
of  these  respective  directions.  Thus  in  rotations  with 
closed  eyes  directed  to  the  left,  there  was  a  marked  ten- 
dency for  the  subject  to  experience  a  sense  of  rotation  in 
the  direction  of  "face  forward,"  whilst  with  the  eyes  turned 
to  the  right  the  tendency  was  to  evoke  a  sensation  of 
rotation  with  "occiput  first,"  and  this,  regardless  of  the 
actual  direction  of  the  rotation  where  there  was  no  sudden 
or  marked  acceleration  or  slowing.  These  phenomena  can 
be  explained  just  as  the  similar  phenomena  noted  in  rota- 
tions in  the  coronal  plane.  Thus,  turning  tlie  eyes  to  the 
right,  by  which  they  were,  in  this  individual,  drawn  up- 
ward, inhibited  vertical  nystagmus  directed  toward  the  feet, 
which  is  associated  with  sagittal  rotations  "face  first," 
whilst  it  favoured  vertical  nystagmus  toward  the  top  of 
the  head,  which  is  associated  with  sagittal  rotations  with 


PHYSIOLOGY  197 

''occiput  first."  Similarly,  on  looking  to  the  left,  the  eyes 
were  directed  toward  the  feet,  which  inhibited  vertical 
nystagmus  toward  the  head  and  favoured  it  toward  the  feet, 
thereby  evoking  the  sensation  of  rotation  "face  first." 

It  would  seem  that  in  every  form  of  nystagmus  due  to 
rotation  there  is,  apart  from  the  secondary  phenomena,  a 
tendency  to  a  superposed  subordinate  mild  nystagmus  in 
the  direction  opposite  to  that  of  the  primary  nystagmus. 
This  subordinate  nystagmus  may  be  so  enhanced  by  turning 
the  eyes  in  the  direction  that  favours  it  and  suppresses 
nystagmus  in  the  opposite  direction,  as  to  completely  over- 
shadow the  latter  in  its  effects.  The  bilateral  relation  of 
the  peripheral  vestibular  apparatus  to  the  cerebellum  may 
account  for  this  twofold  nystagmus,  the  more  extensive 
relation  predominating  in  its  effects  under  ordinary  cir- 
cumstances, whilst  under  the  exceptional  circumstances 
mentioned  the  nystagmus  originated  under  the  influence 
of  the  lesser  relation  is  permitted  to  predominate.  It  is  a 
matter  of  ordinary  experience,  however,  that  strongly  turn- 
ing the  eyes  in  any  one  direction  tends  to  develop  nystag- 
mus in  that  direction.  This  seems  to  indicate  that  the 
overlapping  functions  of  the  ocular  muscles  is  in  great 
part  responsible  for  subsidiary  latent  forms  of  nystagmus. 


CHAPTER  XIV 

THE  EFFECTS  OF  ROTATION  UPON  THE  EYES 

During  rotations,  certain  movements  of  the  eyeballs 
occur  which  are  nystagmic  in  character,  but  which  bear  a 
constant  relation  to  the  plane  and  direction  of  the  rotation. 
These  movements  of  the  eyes  have  been  called  nystagmus, 
though  there  is  nothing  about  them  suggestive  of  the  sleepy 
noddings  which  the  word  implies.  On  the  contrary,  they 
are  an  exaggeration  of  finely  coordinated  reflex  move- 
ments intended  to  aid  visual  fixation  during  the  progress 
of  the  body,  through  space,  or  whilst  objects  move  rapidly 
past  the  body,  the  latter  being  stationary.  A  familiar  in- 
stance of  their  occurrence  under  ordinary  circumstances  is 
the  well-known  behaviour  of  an  individual's  eyes  as  he 
watches  near-by  objects  from  a  rapidly  moving  train.  The 
eyes  in  a  series  of  rapid  jerks,  during  which  vision  is 
impossible,  jump  in  the  direction  in  which  the  subject's 
body  is  moving,  and  then,  fixing  on  the  object  to  be  seen, 
follow  it  with  a  movement  in  the  opposite  direction.  The 
latter  movement  has  just  enough  speed  to  keep  the  image 
of  the  object  in  a  fixed  position  upon  the  retina,  or  as 
near  to  it  as  possible.  Vision  is,  of  course,  possible  during 
this  second  or  slow  movement,  for  the  aim  and  object  of 
both  movements  is  to  render  vision  as  distinct  as  possible. 
Although  distinctly  a  misnomer  etymologically,  the  term 
nystagmus,  out  of  deference  to  ancient  usage,  is  retained. 

In  speaking  of  this  nystagmus,  the  direction  of  it  is  in 
every  instance  to  be  understood  as  meaning  the  direction  of 
the  short  movements  during  which  vision  is  impossible. 
During  a  rotation  from  right  to  left  about  the  vertical 
axis,  i.e.,  in  the  horizontal  plane,  with  the  subject  sitting 
upright,  nystagmus  occurs  in  the  horizontal  plane  and  in 
the  direction  in  which  the  body  is  moving,  i.e.,  toward  the 
left.     If  the  swing  be  suddenly  interrupted  or  abruptly 

198 


PHYSIOLOGY  199 

slowed,  it  will  be  found  tliat  horizontal  nystagmus  is  pres- 
ent, but  directed  toward  the  right,  i.e.,  in  the  reverse 
direction  of  that  which  it  had  during  the  rotation.  If  the 
eyes  be  kept  closed  during  the  progress  of  the  swing,  never- 
theless, they  will  be  found  to  be  in  nystagmus  directed 
toward  the  left,  and  on  interruption  or  slowing  of  the 
swing,  with  the  eyes  still  closed,  the  subject  will  experience 
a  sense  of  movement  in  the  opposite  direction  to  that  in 
which  he  may  still  be  actually  moving,  and  at  the  same 
time  the  direction  of  the  nystagmus  shifts  and  is  now 
directed  to  the  right,  that  is,  in  the  same  direction  in  which 
the  subject  believes  his  body  to  be  rotating.  If,  at  this 
moment,  the  eyes  be  opened,  all  subjective  sense  of  move- 
ment of  the  body  ceases,  but  external  objects  appear  to  be 
moving  from  left  to  right.  Some  authors  have  termed  this 
latter  phenomenon  the  externalization  of  vertigo.  The 
explanation  is  very  simple.  During  the  excursion  of  the 
eyeball  in  the  direction  of  the  nystagmus — in  this  instance 
from  left  to  right — vision  is  impossible,  but  in  the  return 
movement  of  the  eye  from  right  to  left  the  images  of 
external  objects,  seen  after  the  commencement  of  the  slow 
movement,  fall  upon  successive  areas  of  the  retina  which 
are  located  farther  and  farther  toward  the  left  of  the 
fundus  as  the  eye  rotates  to  the  left.  This  shifting  of  the 
images  of  objects  along  the  retina  from  right  to  left  is 
plausibly  mistaken  for  an  actual  movement  of  external 
objects  from  left  to  right,  and  as  vision  is  impossible 
during  the  rapid  movements  of  the  eye  from  left  to  right, 
the  result  is  an  apparent  continuous  movement  of  objects 
from  left  to  right.     (See  diagrams.) 

In  very  rapid  rotations  about  the  long  axis,  more  espe- 
cially if  the  subject  lean  backward  so  that  there  is  a 
coronal  element  in  the  rotation,  the  n^^stagmus  may  not 
be  of  the  purely  horizontal  type,  but  may  be  associated 
with  a  rotary  element  about  the  antero-posterior  axis  of 
the  eyeball.  The  direction  of  this  nystagmus  in  rotations 
from  right  to  left  is  primarily,  i.e.,  during  the  actual  rota- 
tion before  slowing  has  taken  place,  in  the  direction  of 
the  hands  of  the  watch  (with  the  latter  so  placed  against 
the  breast  of  the  subject  that  its  face  looks  toward  the 
observer)  J  whilst  secondarily,  i.e.,  on  sudden  stopping  or 


200 


SEMICIRCULAR   CANALS 


slowing  of  the  swing,  the  direction  is  against  the  hands  of 
the  watch. 

In  the  presence  of  mixed  nystagmus,  external  objects 
in  general  appear  to  move  in  the  direction  of  the  hori- 
zontal element.  The  apparent  movement  imparted  to  them 
by  the  rotary  element  of  the  nystagmus  varies,  depending 
on  which  side  of  the  central  sagittal  meridian  of  the  eye 
the  objects  are  seen  from,  i.e.,  whether  from  the  right  or 
left  of  the  individual. 


Diagrams  to  illustrate  the  apparent  movement  of  objects  in 
horizontal  nystagmus.     See  text  for  explanation. 

In  the  diagrams,  to  illustrate  the  apparent  movement  of 
objects  in  horizontal  after-nystagmus,  the  dotted  arrow 
shows  the  direction  of  the  nystagmus.  The  image,  X,  in 
the  slow  return  movement  of  the  eye,  falls  upon  succes- 
sive areas  of  retina  placed  farther  and  farther  to  the  left 
of  the  fundus  on  account  of  the  rotation  of  the  eyeball 


PHYSIOLOGY  201 

from  right  to  left  about  its  yertical  axis.  This  rotation 
causes  the  anterior  half  of  the  eyeball  to  rotate  toward  the 
left,  and  the  posterior  half  to  rotate  toward  the  right,  with 
the  result  that  the  image  on  the  retina  appears  to  move 
toward  the  left.  This  is  interpreted  as  a  movement  of 
external  objects  toward  the  right.  Figure  A  shows  X',  the 
location  on  the  retina  of  the  image  of  X,  at  the  com- 
mencement of  the  slow  return  movement  of  the  eye  from 
right  to  left.  Figure  B  shows  the  location  of  the  same 
image  a  moment  later.  Figure  C  shows  the  location  on 
the  retina  of  the  image  X'  at  the  end  of  the  slow  return 
movement,  just  before  the  commencement  of  the  rapid 
series  of  jerks  to  the  right.  During  the  progress  of  the 
slow  movement,  the  degree  of  apparent  displacement  of  the 
retinal  image  X'  corresponds  w^ith  what  would  occur  in 
an  actual  movement  of  the  external  object  X  from  the 
left  to  the  right  of  the  subject  if  the  eyes  were  stationary. 


kr— 


Diagram  to  illustrate  the   apparent  movement   of  objects   in 
rotary  nystagmus.      For  explanation  see  text. 

In  the  diagram  illustrating  the  apparent  movement  of 
objects  in  rotary  nystagmus,  the  dotted  arrow  represents 
the  direction  of  the  short,  rapid  element,  whilst  the  con- 
tinuous arrow  represents  the  direction  of  the  slow  element. 
An  object  at  A  to  the  right  of  the  subject  casts  its  image 
at  a  on  the  left  side  of  the  retina.  As  the  fundus  rotates 
slowly  with  the  watch,  the  image  at  a  soon  falls  upon  suc- 
cessively higher  areas  of  the  retina,  represented  by  6  and  o 


202  SEmCIRCULAR   CANALS 

of  the  diagram.  This  is  falsely  interpreted  (projected)  as 
a  movement  of  the  external  object  from  A  to  B  and  C, 
respectively,  i.e.,  as  a  movement  from  a  higher  to  a  lower 
position  when  the  object  is  seen  from  the  right  of  the 
individual. 


Diagram  to  illustrate    the   apparent   movement  of  objects  in 

rotary  nystagmus. 

In  the  second  diagram,  illustrating  the  apparent  move- 
ment of  objects  in  rotary  nystagmus,  an  object  at  A  to 
the  left  of  the  subject  casts  its  image  at  a  on  the  right  side 
of  the  fundus.  Owing  to  the  slow  rotation  of  the  fundus 
with  the  watch,  the  image  at  a  soon  falls  on  successively 
lower  areas  of  the  retina,  represented  by  h  and  c  in  the 
diagram.  This  is  falsely  interpreted  (projected)  as  a 
movement  upward  of  the  object  at  A  to  the  points  B  and  C, 
respectively.  Thus,  because  the  slow  element  of  the  rotary 
nystagmus  is  with  the  hands  of  the  watch,  objects  seen 
from  the  left  of  the  subject  seem  to  ascend,  because  their 
images  fall  upon  successively  lower  areas  on  the  right  half 
of  the  fundus.  The  moment,  however,  that  the  eye,  in  its 
horizontal  movement,  reaches  a  position  in  which  the 
objects  seen  are  situated  on  the  right  of  the  central  sagit- 
tal meridian,  so  that  their  images  fall  upon  the  left  half 
of  the  retina,  then  because  the  slow  rotary  element  is  with 
the  hands  of  the  watch  the  images  appear  upon  successively 
higher  areas  of  the  retina,  and  external  objects,  now  seen 
from  the  right  of  the  individual,  seem  to  move  downward. 
These  facts,  which  are  in  full  accord  with  the  principles 


PHYSIOLOGY  203 

of  optics,  should  be  constantly  borne  in  mind,  as  they 
afford  a  satisfactory  explanation  of  the  apparent  contradic- 
tions of  necessity  encountered  wherever  the  findings  in  the 
study  of  rotary  nystagmus  are  recorded. 

In  rotations  in  the  coronal  plane,  the  dominant  type  of 
nystagmus  is  the  rotary  with  a  horizontal  element  admixed. 
In  rotations  with  the  hands  of  the  watch,  the  rotary  ele- 
ment is  directed  primarily,  i.e.,  during  the  actual  rotation 
and  before  slowing  has  occurred,  in  the  direction  of  the 
hands  of  the  watch,  the  horizontal  element  being  directed 
toward  the  left;  whilst  secondarily,  i.e.,  on  slowing  or 
sudden  stopping  of  the  rotation,  the  rotary  element  is 
directed  against  the  watch  and  the  horizontal  element 
toward  the  right.  During  the  secondary  nystagmus,  ex- 
ternal objects  appear  to  move  around  the  subjects  body  in 
the  coronal  plane,  and  in  the  direction  against  the  hands 
of  the  watch,  that  is,  upward  on  the  left  side  over  the  head 
and  downward  on  the  right.  In  the  study  of  rotary  nystag- 
mus, however,  many  irregularities  are  encountered,  since 
the  horizontal  element  is  frequently,  in  this  form  of 
nystagmus,  the  result,  not  of  coordinated  action,  but  of 
the  peculiarities  in  the  arrangement  of  the  muscles  in- 
volved. Owing  to  the  insertion  of  the  superior  and  inferior 
oblique  behind  the  centre  of  rotation  of  the  eyeball 
(Fuchs^^^),  there  is,  in  rotary  nystagmus,  a  tendency  to 
the  production  of  a  horizontal  element  of  different  direc- 
tion in  either  eye.  Thus,  in  rotary  nystagmus  against  the 
watch  the  short  elements  of  the  nystagmus  result,  in  the 
right  eye,  mainly  from  short,  rapid  contractions  in  the 
inferior  oblique  of  that  eye,  whilst  in  the  left  eye,  the  simi- 
lar movements  are  to  be  attributed  to  rapid  contractions  in 
the  superior  oblique  of  that  eye.  These  contractions  are 
responsible  for  the  short  elements  of  the  rotary  nystagmus 
against  the  watch.  The  secondary  effects  of  the  contrac- 
tions, however,  cause  a  tendency  to  produce  short  hori- 
zontal movements  toward  the  right  in  the  right  eye,  and 
toward  the  left  in  the  left  eye.  Such  irregularities  of 
function  of  the  muscular  apparatus  of  the  eyeball  are 
ordinarily  compensated  by  the  action  of  the  other  ocular 
muscles.  Strongly  turning  the  eye  from  one  side  to  the 
other,  tends  to  develop  the  irregularity  in  one  eye  and  to 
suppress  it,  perhaps,  in  the  other.     It  is  owing  to  the 


204  SEMICIRCULAR   CANALS 

development  or  suppression  of  various  forms  of  nystagmus 
that,  b}'  strongly  turning  the  closed  eyes  in  one  direction 
or  another,  the  subject  can  influence  the  subjective  sense  of 
motion  he  experiences  during  or  after  rotations. 

Since  in  rotations  these  movements  occur  with  the 
eyes  closed,  and  because  various  physiologists  have  observed 
nystagmus  on  direct  stimulation  of  the  semicircular  canals, 
it  is  fair  to  conclude  that  in  rotations  nystagmus  is  mainly 
the  result  of  irritation  of  certain  labyrinthine  receptors, 
depending  upon  the  form  of  nystagmus  produced.  The 
labyrinthine  nystagmus  caused  refiexly  when  the  body  is 
rotated,  is  a  physiological  process  intended  to  facilitate 
visual  fixation,  and  is  associated  with  other  reflex  com- 
pensatory movements  (synkineses),  also  of  lab3Tinthine 
origin.  However,  where  the  body  is  stationary  and  an 
attempt  is  made  at  visual  fixation  of  rapidly  passing  ob- 
jects, a  visual  nystagmus  is  evoked  through  the  retinal 
receptors.  It  is  probable  that  in  rotations  with  the  eyes 
open,  the  nystagmus  is  the  result  of  impulses  generated  in 
both  retinal  and  labyrinthine  receptors  impinging  jointly 
upon  the  same  final  common  paths. 

In  rotations  in  the  sagittal  plane,  nystagmus  of  the 
vertical  type  occurs.  Rotation  in  the  sagittal  plane  with 
the  "face  first"  caused  vertical  nystagmus,  which  was 
primarily  directed  toward  the  feet,  and  secondarily,  i.e., 
after  slowing  or  stopping  of  the  swing,  toward  the 
top  of  the  head.  External  objects  "just  wobbled,"  with  a 
general  tendency  of  moving  from  the  feet  toward  the  head. 
It  was  a  noticeable  feature  in  rotations  in  the  sagittal 
plane,  with  the  face  forward,  that  the  nystagmus  was  never 
so  intense  as  that  seen  in  rotations  in  the  same  plane 
with  "occiput  first,"  nor  had  the  rotations  the  same  ten- 
dency to  distress  and  sicken  the  subject.  Rotations  in  the 
sagittal  plane  with  the  "occiput  first"  caused  furious 
vertical  nystagmus,  directed  primarily  toward  the  top  of 
the  head,  and  secondarily,  toward  the  feet.  During  the 
after-nystagmus  external  objects  seemed  to  move  rapidly 
and  steadily  toward  the  feet  from  the  head  in  the  sagittal 
plane. 

In  rotations  about  a  diagonal  transverse  axis  at  the 
level  of  the  umbilicus,  i.e.,  in  a  plane  midway  between  the 
coronal  and  sagittal^  with  the  subject  lying  partly  on  the 


PHYSIOLOGY  205 

left  side  and  partly  on  the  back,  the  chief  type  of  nystag- 
mus was  vertical  in  direction,  but  with  a  rotary  element 
added.  Eotations  in  this  plane  with  "occiput  first"  caused, 
primarily,  vertical  nystagmus  toward  the  top  of  the  head, 
with  a  rotary  element  against  the  watch.  The  after- 
nystagmus  was  toward  the  feet,  with  a  rotary  element 
directed  with  the  watch.  External  objects  seemed  to  move 
from  the  head  to  the  feet,  with  a  slight  diagonal  deviation 
toward  the  left  foot.  At  times  they  seemed  to  move  over 
the  head  from  right  to  left,  with  the  watch  in  a  plane 
between  the  coronal  and  the  sagittal.  During  the  rota- 
tion, on  looking  strongly  toward  the  right,  objects  flew  past 
the  face  from  right  to  left.  During  the  "after-nystagmus," 
on  turning  the  eyes  strongly  to  the  left,  external  objects 
seemed  to  move  about  the  body  in  the  direction  of  the 
hands  of  the  watch,  and  at  the  same  time  showed  a  distinct 
rotary  nystagmus  with  the  watch.  This  latter  was  in- 
hibited by  looking  toward  the  right.  On  another  occa- 
sion during  the  after-nystagmus,  objects  seemed  to  the 
subject  to  travel  in  two  directions,  viz.,  (1)  about  his  body, 
partly  in  the  coronal  plane  and  with  the  watch,  and,  (2) 
from  right  to  left  about  the  long  axis  of  the  subject's  body, 
whereby  the  "wall  seemed  to  be  sinking  into  the  ground." 
The  latter  movement  is  accounted  for  by  a  horizontal  ele- 
ment in  the  nystagmus  directed  toward  the  left,  which  at 
times  accompanies  rotary  nystagmus,  and  in  certain  posi- 
tions of  the  eyes  seems  to  dominate  it. 

In  rotations  in  the  diagonal  plane,  "face  first,"  the 
secondary  nystagmus  tends  to  be  mild  and  of  short  dura- 
tion, and  is  directed  chiefly  toward  the  top  of  the  head. 

It  is  noteworthy  that  the  nystagmic  movements  of  the 
eyes  that  accompany  rotation,  i.e.,  acceleration  and  retarda- 
tion, are  wholly  reflex  in  their  nature.  Another  note- 
worthy fact  is,  that  the  nystagmic  movements  during  actual 
rotation  always  bear  a  characteristic  fixed  relation  to  the 
direction  in  which  the  body  is  actually  moving,  whilst  dur- 
ing the  "after-nystagmus"  the  direction  of  the  movements 
of  the  eyeballs  have  a  characteristic  fixed  relation  to  the 
subjective  sense  of  motion  which  the  individual  with  closed 
eyes  experiences.  The  direction  of  this  subjective  sense  of 
motion  is  always  with  the  short  elements,  just  as  the  short 
elements  of  the  primary  nystagmus  are  always  of  the  same 


206  SEMICIRCULAR   CANALS 

direction  as  that  of  the  actual  rotation.  These  two  facts, 
fundamental  in  importance,  suffice  for  present  purposes. 
The  fuller  discussion  of  the  subject  will  receive  attention 
under  aural  irrigations  where  the  intricate  movements  of 
the  eyes  were  studied  with  the  aid  of  the  ophthalmoscope. 

The  changes  that  occur  in  the  fundus  oculi  during 
rotations  are  mainly  those  dependent  upon  altered  condi- 
tions of  the  blood-vessels.  Just  after  a  violent  rotation 
the  arteries  were  generally  found  contracted  and  practically 
empty.  This  condition  was  soon  followed  by  dilatation, 
and  more  or  less  congestion.  Like  nystagmus,  this  part 
of  the  subject,  as  well  as  the  behaviour  of  the  pupils,  is 
best  studied  during  aural  irrigations. 

In  rotations,  turning  the  eyes  constantly  from  one 
side  to  the  other  and  concentrating  the  attention,  had  a 
powerful  effect  in  upsetting  the  general  organism  and  caus- 
ing distress.  This  was  most  noticeable  in  a  series  of  rota- 
tions in  the  coronal  plane,  with  the  subject  lying  supine, 
where,  under  ordinary  circumstances,  we  might  expect  the 
least  effect  upon  gastric  motility,  nausea,  etc. 


CHAPTER  XV 
THE   GENERAL   EFFECTS   OF   AURAL   IRRIGATIONS 

The  effects  of  irrigations  of  the  external  auditory  canal 
resemble,  in  general,  those  of  rotations.  Disturbances  of 
equilibrium,  nystagmus,  circulatory  changes,  nausea,  in- 
creased salivation,  sweating,  pallor,  vomiting,  and  general 
prostration  similar  in  every  particular  to  the  phenomena 
that  accompany  rotations,  occur  when  water  of  a  certain 
temperature  is  allowed  to  flow  continuously  for  two  or 
three  minutes  into  the  external  auditory  canal.  New  and 
interesting  features,  however,  are  added,  as,  for  instance, 
the  deviation  of  the  head  toward  the  left  with  horizontal 
nystagmus  to  the  right  on  irrigating  the  left  ear  with 
cold  water,  whilst  irrigation  of  the  same  ear  with  hot 
water  produced  similar  phenomena  but  in  the  opposite 
direction,  that  is,  the  head  inclined  toward  the  right,  whilst 
the  nystagmus  was  directed  toward  the  left. 

In  aural  irrigations  the  temperature  of  the  irrigating 
fluid  is  all-important.  In  this  connection,  it  is  to  be 
remembered  that  the  thermic  effect  of  baths  depends  upon 
the  difference  between  the  temperature  of  the  water  used 
and  that  of  the  surface  of  the  body  upon  which  it  is 
applied.  It  also  depends  upon  the  extent  of  surface  to 
which  the  water  is  applied,  as  well  as  upon  the  suddenness 
and  force  of  impact.  As  the  temperature  of  the  human 
skin  ranges  between  90°  and  95°  F.,  with  an  average,  per- 
haps, of  92.5°  F.,  hydriatrists  consider  a  bath  of  93°  F.  or 
thereabout  as  neutral,  i.e.,  neither  hot  nor  cold.  The  same 
rules  regarding  temperature,  etc.,  govern  aural  irrigation, 
but  owing  to  anatomical  and  physiological  peculiarities  the 
thermic  neutral  point  is  some  degrees  higher  for  the  laby- 
rinth than  that  for  the  general  skin  surface.  Generally 
speaking,  aural  irrigations  at  80°  F.  produce  effects  which 
could  not  be  duplicated  By  hot  irrigations  below  110°  F., 

207 


208  SEMICIHCULAR  CANALS 

or,  we  might  say,  perhaps  with  more  accuracy  below  113°  F. 
This  would  bring  the  neutral  point  for  thermal  stimulation 
of  the  labyrinth  close  to  the  internal  body  temperature. 

The  force  under  which  the  fluid  is  driven  into  the 
canal  has  a  certain  effect  in  aural  irrigations,  but  the 
temperature  of  the  fluid  is  the  chief  determining  factor  in 
eliciting  the  characteristic  phenomena.  When  not  other- 
wise mentioned,  the  height  of  the  irrigating  receptacle  in 
the  experiments  is  to  be  understood  as  being  at  1^  feet 
above  the  external  auditory  meatus  in  irrigations  with  the 
subject  sitting  erect,  and  2^^  feet  above  the  meatus  in 
irrigations  with  the  subject  in  the  supine  posture. 

Standing  erect  during  the  progress  of  the  irrigations 
has  a  most  powerful  influence  in  aggravating  some  of  the 
phenomena  and  sickening  the  subject.  Sitting  seems  to 
retard  some  of  the  disagreeable  symptoms,  whilst  lying 
supine  has  the  greatest  effect  in  retarding  them,  especially 
the  nausea  and  vomiting,  although  if  the  irrigations  be 
prolonged  or  severe,  projectile  vomiting  may  result. 

Concentration  of  attention,  as  well  as  muscular  efforts 
at  balancing,  are  important  secondary  factors  in  determin- 
ing sickness  and  prostration.  It  was  noted  in  irrigations 
with  the  subject  lying  supine  that  constantly  turning  the 
closed  eyes  from  one  side  to  the  other  and  concentrating 
the  attention  to  ascertain  the  direction  in  which  the  sub- 
ject believed  his  body  to  be  turning,  very  quickly  brought 
the  sickness  to  a  climax,  thereby  corroborating  the  findings 
in  rotations  under  similar  conditions  of  posture. 

Within  limits  of  moderate  range,  bilateral  irrigations 
with  water  at  the  same  temperature  have  less  tendency  to 
sicken  and  disturb  the  subject's  equilibrium  than  unilateral 
irrigation  with  water  at  the  same  temperature.  With  very 
cold  or  very  hot  bilateral  irrigations,  however,  intense  vom- 
iting can  occur,  though  even  with  these,  the  nystagmus 
seemed  to  be  moderate,  or  even  absent.  Thus,  in  a  bilateral 
irrigation  at  67*^  and  in  another  at  57°  F.  vomiting  oc- 
curred, but  there  was  no  distinct  nystagmus  beyond  a 
slight  jerkiness,  the  direction  of  which  was  doubtful,  but 
which  seemed  to  be  toward  the  top  of  the  head.  There 
was  no  apparent  movement  of  external  objects.  In  bi- 
lateral irrigations,  therefore,  the  vomiting  seems  to  be 
due  to  disturbances  in  the  receptors  in  the  maculae  of  the 


PHYSIOLOGY  S09 

vestibule,  which,  as  before  stated,  are  probably  in  direct 
relation  with  the  nausea  and  vomiting  mechanisms.  The 
receptors  in  the  maculae  on  either  side  of  the  body,  in  so 
far  as  they  directly  affect  the  mechanisms  of  nausea  and 
vomiting,  do  not  seem,  therefore,  to  stand  toward  each 
other  in  the  relation  of  balanced  mechanisms  as  do  the 
ampullary  receptors.  The  macular  receptors,  however,  on 
either  side  of  the  body  are  set  up  against  each  other  as 
balanced  mechanisms,  in  so  far  as  they  affect  other  mechan- 
isms, e.g.,  those  of  equilibration  and  possibly  those  of 
nystagmus. 

Tlie  Effects  of  Aural  Irrigations  upon  the  Circulation 

The  chief  effect  of  cold  or  hot  irrigations  is  an  im- 
mediate rise  in  blood-pressure,  with  a  slowing  of  the  pulse. 
During  the  irrigations,  however,  the  blood-vessels  dilate 
and  contract  to  a  considerable  degree  at  very  short  inter- 
vals. After  the  irrigations  there  is  a  rather  rapid  decline 
in  blood-pressure,  with  a  corresponding  rise  in  pulse-rate. 
(See  protocols  18  to  25,  at  the  end  of  this  chapter.) 

Very  hot  and  very  cold  irrigations,  like  very  hot  or 
very  cold  baths,  have  for  their  immediate  effect  an  eleva- 
tion of  the  blood-pressure.  Irrigations  at  temperatures 
within  the  neutral  limits,  i.e.,  a  few  degrees  above  or  below 
98.4°  F.,  have  little  effect  on  the  circulation  unless  given 
under  high  pressure,  when  the  blood-pressure  will  be  raised 
just  as  in  hot  or  cold  irrigations.  (See  protocol  23b.) 
Similarly,  playing  a  strong  light  on  the  eyes  (protocols 
18a  and  18b),  or  any  powerful  stimulation  of  sensory 
nerves,  raises  the  blood-pressure.  During  the  irrigations 
the  blood-pressure  fluctuated  considerably,  and  so  rapidly 
that  the  figures  in  the  protocols  do  not  represent  the  changes 
fairly.  One  such  instance  of  a  steep  drop  in  blood-pressure 
is  shown  in  protocol  22a,  where  there  was  a  drop  from 
140  mm  of  Hg.  to  80  during  an  irrigation  at  61°  F.  Such 
fluctuations  occurred  so  suddenly  that  usually  there  was 
not  sufficient  time  to  catch  and  record  the  pressures. 

The  changes  in  the  circulation,  therefore,  resemble  those 
that  follow  rotation,  and  are  produced  by  irritation  and 
exhaustion  of  the  same  mechanisms.  The  vaso-motor  sys- 
tem is  in  a  constant  state  of  active  variation,  readily  recog- 


210  SEMICIRCULAR   CANALS 

nized  in  the  radial  pulse  and  in  the  vessels  of  the  fundus 
oculi. 

In  bilateral  irrigations  the  blood-pressure  and  pulse- 
rate  are  affected  about  the  same  as  in  single  irrigations  of 
the  same  temperature.     (See  protocol  23a.) 

The  effects  of  consecutive  irrigations,  both  unilateral 
and  bilateral,  are  shown  in  protocol  23.  Both  kinds  of 
irrigations  have  about  the  same  effect  in  raising  the  blood- 
pressure,  whilst  the  pulse-rate  remains  stationary.  The 
effect  of  a  neutral  irrigation  in  raising  the  blood-pressure 
when  the  fluid  enters  the  auditory  canal  under  pressure,  is 
shown  in  protocol  23b.  With  the  irrigating  receptacle  just 
sufficiently  above  the  ear,  to  insure  a  flow,  the  effect  on  the 
pulse-rate  and  blood-pressure  was  nil,  whereas,  with  the 
receptacle  4^  feet  above  the  ear,  the  blood-pressure  rose 
to  130,  the  pulse-rate  remaining  stationary. 

There  was  little  noticeable  effect  on  the  respiration 
beyond  the  initial  inspiratory  gasp  at  the  commencement 
of  the  irrigations.  When  exhaustion  began  to  set  in,  or 
the  blood-pressure  fell  very  low,  the  respiratory  rate  was 
increased.     (See  protocol  20a.) 

The  Effect  of  Drugs  in  Aural  Irrigations 

The  effect  of  atropin  in  aural  irrigations  was  in  every 
respect  similar  to  its  effect  in  rotations.  The  efficiency  of 
the  vaso-motor  system  was  enhanced  and  the  cardiac 
mechanism  released  from  vagus  control.  Protocols  22b 
and  22c  show  the  action  of  atropin  and  the  response  of 
the  cardiac  and  vaso-motor  mechanisms  to  cold  irrigations. 
Atropin  had  the  same  effect  in  diminishing  nausea  and 
sickness  referable  to  the  stomach  that  it  displayed  in  rota- 
tion sickness.  It  had  no  direct  effect,  however,  in  prevent- 
ing or  diminishing  vertigo,  nystagmus,  or  disturbances  of 
equilibrium. 

Adrenalin  m  iii  intravenously  had  its  well-known  effect 
on  the  blood-pressure.  Its  effect  in  contracting  the  blood- 
vessels was  well  demonstrated  in  the  small  vessels  which 
lie  along  the  handle  of  the  malleus.  These  were  quite 
invisible  after  the  adrenalin,  just  as  they  are  immediately 
after  hot  and  cold  irrigations.  When  the  adrenalin  effects 
had  worn  off,  the  small  vessels  reappeared  and  were  then 


PHYSIOLOGY  211 

seen  to  be  somewhat  dilated,  as  after  aural  irrigations. 
(See  protocol  23c.) 

Adrenalin  was  without  effect  in  combating  the  vertigo, 
nausea,  nystagmus,  and  disturbances  of  equilibrium  that 
are  caused  by  aural  irrigations.  A  3%  solution  of  cocain, 
in  equal  parts  of  analin  oil  and  alcohol,  applied  to  the 
interior  of  the  external  auditory  canal  and  to  the  drum 
membrane,  was  without  effect  upon  the  phenomena  of  irri- 
gations. Pilocarpin  was  tried  and  found  to  have  no  effect 
in  preventing  nystagmus,  vertigo,  nausea,  gastric  disorders, 
or  disturbances  of  equilibrium.  Gr  %  of  the  hydro- 
chlorid  was  given  hypodermically.  In  seven  minutes  the 
forehead  was  moist,  and  in  fourteen  minutes  it  was  thickly 
covered  with  beads  of  sweat.  Irrigations  were  then  given 
with  the  subject  in  the  supine  posture.  The  only  beneficial 
effect  noticed  was  that  the  noise  from  the  irrigation  seemed 
to  be  less  than  usual,  but  as  this  frequently  occurred  where 
no  drug  had  been  used  it  seems  we  are  not  justified  in 
crediting  even  this  to  the  action  of  the  drug.  After  the 
administration  of  the  pilocarpin  there  was  a  gradual  rise 
in  pulse-rate  and  blood-pressure,  followed  later  by  a  grad- 
ual subsidence,  so  that  in  the  course  of  two  hours  the  cir- 
culation was  about  in  the  condition  it  had  been  in  before 
the  administration  of  the  drug.      (See  protocol  24.) 

It  will  be  noted  that  the  effect  of  pilocarpin  upon  the 
circulation  in  this  instance  differs  from  that  generally 
ascribed  to  the  drug.  Usually  pilocarpin  slows  the  heart 
by  stimulation  of  the  cardiac  vagus  endings,  and  lowers 
the  blood-pressure  by  depression  of  the  vaso-constrictor 
centre  in  the  medulla.  The  absence  of  the  usual  effects  of 
the  drug  upon  the  circulation  in  this  instance  may  be 
explained  by,  (1)  the  moderate  dosage,  although  the  effect 
upon  the  salivary  and  sweat  glands  was  pronounced;  (2) 
the  counteracting  effect  of  the  psychic  condition  and  of 
surrounding  circumstances  (the  subject  had  been  a  long 
time  anticipating  this  test  and  during  the  experiment  he 
lay  on  the  table  with  very  little  clothing  on  him,  as  the  day 
was  warm)  ;  (3)  the  idios3'ncrasies  of  the  individual  who 
seldom  sweats,  and  never  profusely,  and  whose  circulatory 
mechanism  is  strong  at  the  cardiac  end,  and  perhaps  rela- 
tively feeble  at  the  vaso-motor  end. 

The  evidence  brought  forth  by  these  experiments  does 


212  SEMICIRCULAR   CANALS 

not  tend  to  support  those  clinicians  (Politzer,  Lermoyez, 
and  others)  who  claim  so  much  for  pilocarpin  in  inflam- 
matory and  other  conditions  affecting  the  internal  ear. 

The  effect  of  hypnotic  suggestion  upon  the  phenomena 
evoked  by  aural  irrigations  was  studied  extensively.  Fol- 
lowing are  some  of  the  notes  taken  during  the  experiments : 
Irrigation  at  72°  F.  of  the  left  ear  for  three  minutes  in  a 
subject  with  normal  hearing  in  both  ears  caused  the  usual 
phenomena  with  nystagmus  and  apparent  movement  of 
objects  to  the  right.  In  waking  hypnosis,  with  the  sug- 
gestion that  it  would  not  make  him  sick,  dizzy,  etc., 
another  irrigation  at  72°  F.  was  given.  The  head  did  not 
seem  to  fall  one  way  or  the  other.  The  subject  was  made 
very  dizzy,  but  stated  he  did  not  feel  the  "loss  of  the  sup- 
ports'^ of  the  head  on  either  side.  There  was  slight  visible 
nystagmus,  but  the  eyes  were  kept  closed  and  turned 
strongly  upw^ard,  whilst  the  subject  manifested  a  strong 
tendency  to  sleep.  After  the  irrigation,  and  whilst  still  in 
hypnosis,  the  subject  walked  without  staggering,  but  the 
gait  was  slow  and  studied,  every  step  being  apparently 
made  with  the  greatest  possible  care.  The  subject  was 
rather  quickly  taken  out  of  hypnosis  and  at  once  lost  his 
balance. 

A  little  later,  with  eyes  closed,  he  tried  to  stand  first 
on  the  left  foot,  and  then  on  the  right.  In  each  case  it 
was  impossible  for  him  to  steady  himself.  He  was  com- 
pelled to  make  a  constant  succession  of  hops  in  order  to 
maintain  his  equilibrium.  When  attempting  to  stand  on 
the  right  foot  the  hops  were  made  toward  the  right,  and 
when  attempting  to  stand  on  the  left  foot  the  hops  were 
made  toward  the  left.  The  same  subject,  on  a  subsequent 
occasion,  received  an  irrigation  in  the  left  ear  at  70°  F. 
but  without  hypnosis.  The  usual  phenomena  were  mani- 
fested. After  the  irrigation,  on  attempting  to  stand  on 
either  leg  the  subject  fell  toward  the  left,  but  after  a  time 
there  was  a  slight  reactionary  tendency  to  fall  to  the  right. 

Under  hypnosis,  with  the  suggestion  that  the  irriga- 
tion would  not  disturb  him,  an  irrigation  of  70°  F.  for  four 
minutes  was  given  in  the  left  ear.  The  visible  nystagmus 
was  not  nearly  as  pronounced  as  might  have  been  expected 
from  such  an  irrigation.  After  the  irrigation  the  subject, 
still  in  hypnosis,  balanced  well  on  either  foot. 


PHYSIOLOGY  218 

A  prolonged  irrigation  at  70°  F.  was  given  under  hyp- 
nosis, with  the  suggestion  that  it  was  warm  water.  The 
subject  manifested  great  comfort  in  his  facial  expression, 
but  at  times  made  the  usual  wry  faces.  Nystagmus  to  the 
right  was  manifested,  but  it  was  not  so  apparent  as  one 
should  expect.  After  the  irrigation,  and  still  in  h}^nosis, 
the  subject  stood  well  with  the  feet  close  together,  and  with 
eyes  closed,  but  he  was  unable  to  balance  on  one  foot  with 
eyes  open  or  closed. 

It  was  noted  that  during  the  irrigations  the  left  pupil 
was  smaller  than  the  right.  The  knee-jerks  were  slightly 
increased.  Under  the  suggestion  that  the  knee-jerks  were 
exaggerated,  the  motor  response  to  the  tendon  tap  was 
slow  and  of  wide  range,  suggestive  of  voluntary  extension 
of  the  leg  rather  than  of  the  sharp  response  of  the  true 
reflex. 

On  another  occasion  the  same  subject  was  put  through 
balancing  tests  before  irrigation  was  practised.  It  was 
found  that  with  the  eyes  open  he  could  stand  well  with 
both  feet  close  together  and  on  either  foot,  whereas,  with 
the  eyes  closed  he  could  stand  on  both  feet,  but  not  very 
well  on  either  foot  alone.  The  pupils  were  observed  to  be 
rather  small.  Before  irrigation,  the  pulse-rates  were  60, 
72,  72,  with  corresponding  blood-pressures  of  120,  120, 
115.     (See  protocol  25.) 

Irrigation  at  69°  F.  in  left  ear  without  hypnosis  caused 
the  usual  phenomena.  During  the  irrigation  the  pulse- 
rates  were  68,  68,  with  blood-pressures  of  120  and  120. 
After  the  irrigation,  with  the  eyes  open  he  could  not  stand 
well  on  either  foot,  but  tended  to  fall  to  either  side. 

Under  waking  hypnosis  the  pulse-rates  were  68,  68, 
with  blood-pressure  of  115  and  115.  With  the  suggestion, 
that  he  was  receiving  a  cold  irrigation  in  the  left  ear,  the 
subject  made  wry  faces  and  behaved  as  if  he  were  actually 
receiving  a  cold  irrigation,  although  no  irrigation  whatever 
was  given.  Both  pupils  were  moderately  dilated,  but  the 
left  was  smaller  than  the  right.  There  was  no  hippus 
present.  On  looking  to  the  right,  the  eyes  jerked  slightly 
that  way,  and  the  head  inclined  toward  the  left.  There 
seemed  to  be  an  awkward  attempt  at  reproducing  an  irreg- 
ular type  of  nystagmus. 

Before  irrigation  the  pulse-rate  was  64,  and  the  blood- 


214  SEMICIRCULAR   CANALS 

pressure  115.  An  irrigation  at  69°  F.  w'as  given  in  the 
left  ear  for  three  minutes,  with  the  subject  in  hypnosis,  and 
with  the  suggestion  that  it  was  a  pleasant,  tepid  irrigation 
which  would  not  disturb  him  or  make  his  eyes  jerk.  One 
minute  after  starting  the  irrigation  the  pulse-rate  was  64, 
and  the  blood-pressure  115.  There  was  scarcely  any  nystag- 
mus present,  and  that  chiefly  on  looking  to  the  right. 
The  head  did  not  fall  to  the  left  after  the  irrigation,  and 
the  subject  walked  well,  even  with  the  eyes  closed.  The 
gait,  however,  was  painfully  slow  and  studied.  On  being 
taken  out  of  hypnosis  he  stood  and  walked  well,  but  he 
relapsed  so  quickly  into  hypnosis  that  it  was  doubtful 
whether  he  had  been  thoroughly  aroused  from  the  hypnotic 
state. 

An  irrigation  at  68°  F.  was  given  in  the  left  ear,  but 
without  hypnosis.  The  usual  nystagmus,  etc.,  were  mani- 
fested. After  the  irrigation,  the  subject  stood  well  with  the 
eyes  closed,  and  appeared  to  stand  better  on  the  foot  of  the 
side  irrigated  than  on  the  opposite  foot.  In  the  last  in- 
stance he  fell  generally  toward  the  side  of  irrigation. 

Under  hypnosis  a  cork  was  placed  in  the  subject's  out- 
stretched hand,  with  the  suggestion  that  it  was  a  heavy 
weight.  Appropriate  grunts  and  gestures  were  made  as 
though  a  heavy  w^eight  was  sustained  at  a  great  disad- 
vantage, but  little,  if  any,  perceptible  change  in  the  pulse- 
rate  or  blood-pressure  was  registered. 

On  another  occasion  the  subject  was  tested  before  irri- 
gations were  practised.  With  closed  eyes  he  stood  fairly 
well  on  either  foot,  but  lost  his  balance  after  three  seconds. 
Standing  on  the  left  foot,  he  lost  his  balance  toward  the 
left.  Standing  on  the  right  foot,  he  lost  his  balance  toward 
the  right. 

An  irrigation  of  the  left  ear  at  69°  F.  caused  marked 
nystagmus  in  less  than  one  minute.  After  the  irrigation 
the  subject,  wdth  eyes  closed,  was  unable  to  stand  on  either 
foot.    Tbis  disability  persisted  for  one  or  two  minutes. 

Irrigation  of  left  ear  at  111°  F.  caused  some  nystagmus. 
Irrigation  at  116°  F.  caused  well-marked  nystagmus.  After 
the  irrigation  the  subject  was  unable  to  stand  on  either  foot 
with  the  eyes  closed.  After  an  irrigation  in  the  left  ear  at 
120°  F.  the  subject,  with  eyes  open,  stood  better  on  the 


PHYSIOLOGY  215 

right  foot  than  on  the  left.  With  e5^es  closed,  he  was 
unable  to  stand  on  either  foot,  but  made  better  attempts 
to  stand  on  the  right.  The  subject,  after  a  short  rest,  was 
hypnotized  and  an  irrigation  at  69°  F.  of  the  left  ear 
given,  with  the  suggestion  that  the  water  was  tepid  and 
soothing,  and  would  not  make  the  eyes  jump,  etc.,  or  dis- 
turb his  balance.  Violent  nystagmus  was  manifested  early 
during  the  irrigation.  After  the  irrigation,  with  eyes 
closed,  he  balanced  well  standing  on  both  feet,  but  did  so 
very  awkwardly  on  one  foot,  making  wide  sweeps  of  the 
opposite  leg  in  order  to  maintain  his  balance,  and  being 
finally  compelled  to  touch  the  floor. 

Using  the  same  subject,  before  irrigation  the  pulse-rates 
were  84,  92,  84,  and  84,  with  corresponding  blood-pressures 
of  110,  110,  110,  and  110.  An  irrigation  of  the  left  ear 
was  given  at  69°  F.  During  the  irrigation  the  pupils  were 
moderately  dilated,  the  left  being  smaller  than  the  right, 
whilst  the  pulse-rates  were  76  and  76,  the  blood-pressures 
being  115  and  115.  After  the  irrigation,  the  subject  was 
dull  and  heavy.  He  had  evidently  gone  into  hypnosis.  He 
was  unable  to  stand  with  eyes  closed,  and  could  not  lift  one 
foot  from  the  ground  without  falling. 

Under  hypnosis  before  irrigation,  the  pulse-rate  was  76 
and  the  blood-pressure  115.  An  irrigation  at  69°  F.  was 
given  in  the  left  ear  under  hypnosis,  and  with  the  sugges- 
tion that  the  water  was  tepid  and  would  not  sicken  or 
disturb  him.  During  the  irrigation  the  pupils  at  first  con- 
tracted and  then  became  moderately  dilated,  but  the  left 
remained  smaller  than  the  right.  There  was  well-marked 
nystagmus  to  the  right.  During  the  irrigation  the  pulse 
was  76,  and  the  blood-pressure  120,  with  the  artery  well 
contracted.  After  irrigation  the  subject  balanced  much 
better  than  he  did  after  the  previous  irrigation,  and  yet 
both  irrigations  were  of  the  same  temperature  and  duration. 
However,  it  was  only  with  great  difficulty  that  he  could 
stand  on  one  foot. 

Before  being  put  into  general  cataleptic  rigidity,  the 
pulse-rate  was  72  and  the  blood-pressure  110.  During 
general  cataleptic  rigidity  the  pulse-rate  was  76  and  the 
blood-pressure  110.  The  suggestion  was  made  to  the  sub- 
ject that  he  supported  upon  his  outstretched  hand  a  weight 


216  SEMICIRCULAR   CANALS 

of  100  pounds.  During  the  efforts  he  made  to  support  this 
imaginary  weight  the  pulse-rate  was  80  and  the  blood- 
pressure  115. 

On  another  occasion,  examination  of  the  subject  before 
the  irrigations  and  without  hypnosis  showed  the  pulse-rate 
to  be  84,  84,  88,  and  88,  the  blood-pressures  being  115, 
115,  115,  and  110.  Under  hypnosis  the  pulse-rates  were 
76,  76,  84,  88,  and  the  blood-pressures  115,  115,  120,  and 
115.  An  irrigation  of  the  left  ear  at  115°  F.  was  given 
under  hypnosis,  and  with  the  suggestion  that  the  water  was 
warm  and  agreeable  and  would  not  cause  '^jumping  of  the 
eyes"  or  other  disturbance.  During  the  irrigation  the 
pupils  were  moderately  dilated,  but  the  left  was  a  little 
smaller  than  the  right.  The  head  was  inclined  to  fall  to 
the  right.  There  was  no  visible  nystagmus.  During  the 
irrigation  the  pulse-rates  were  76,  80,  80,  88,  and  the 
blood-pressures  110,  110,  110,  and  105. 

An  irrigation  of  the  left  ear  at  120°  F.  was  given  under 
hypnosis,  and  with  the  suggestion  that  it  would  sicken  him 
and  make  him  vomit.  The  subject  made  all  sorts  of 
attempts  to  vomit,  but  there  was  no  actual  vomiting. 
During  the  irrigation,  with  the  attempts  at  vomiting  the 
pulse-rates  were  84,  88,  88,  whilst  the  blood-pressures  were 
110,  130,  and  135. 

An  irrigation  at  64°  F.  in  the  left  ear  was  given,  with 
the  suggestion  that  it  would  sicken  the  stomach  and  cause 
vomiting.  There  were  occasional  attempts  at  vomiting. 
During  the  irrigation  the  pulse-rates  were  84,  76,  84,  84, 
84,  96,  92,  84,  84,  84,  84,  92,  and  92,  with  corresponding 
blood-pressures  of  125,  115,  125,  125,  130,  115,  115,  115, 
115,  115,  110,  105,  and  105. 

After  an  irrigation  of  left  car  at  64°  F.  the  subject  was 
immediately  put  into  general  catalepsy  in  the  standing 
position,  with  the  feet  a  little  apart,  so  as  to  insure  proper 
balance.  In  this  condition  he  was  more  easily  pushed  over 
to  the  left  than  to  the  right. 

An  irrigation  of  the  left  ear  was  given  at  123°  F.  under 
hypnosis,  but  without  any  particular  suggestion.  There 
was  no  nystagmus,  even  on  looking  to  the  right  or  left. 
After  the  irrigation,  on  being  made  rigid  he  was  stiff 
toward  either  side  as  he  sat  on  the  stool,  but  on  being 


PHYSIOLOGY  217 

made  rigid  in  the  standing  position  he  was  easily  pushed 
over  to  the  right.  He  could  not  readily  be  pushed  over 
to  the  left^  but  it  took  very  little  force  to  make  him  lose 
his  balance  toward  the  right.  In  the  latter  direction,  on 
being  pushed  the  subject  toppled  over  like  a  statue.  He 
seemed  to  be  unable  to  make  any  effort  at  recovering  his 
balance  when  his  equilibrium  was  displaced  to  the  right. 

During  irrigation  of  left  ear  at  62°  ¥.,  under  hypnosis, 
with  the  subject  standing  and  in  a  state  of  general  cata- 
leptic rigidity,  there  was  nystagmus  toward  the  right,  and 
the  subject  at  first  toppled  over  to  the  right,  then  to  the 
left,  and  later  on  in  various  directions.  His  feet  were 
close  together. 

An  irrigation  of  the  left  ear  at  62°  F.  was  given  the 
subject  as  he  stood  with  the  feet  wide  apart  and  the  neck 
and  head  in  a  state  of  cataleptic  rigidity.  There  was 
nystagmus  to  the  right,  but  the  head  did  not  incline  to 
either  side.  On  closing  the  eyes,  the  subject  felt  himself 
revolving  from  right  to  left  (probably  an  error)  about  his 
long  axis.  The  irrigation  was  repeated  with  the  subject 
rigid  from  the  head  down,  but  with  the  head  and  neck 
loose  and  free.  During  the  irrigation  the  head  fell  freely 
toward  the  left  side. 

A  bilateral  irrigation  at  62°  F.  was  given,  with  the 
subject  in  general  cataleptic  rigidity  and  standing  in  a 
natural  attitude.  During  the  irrigation  the  subject  at 
first  fell  backward  and  had  to  be  supported.  Later  he 
was  inclined  to  topple  over  in  various  directions.  After 
the  irrigation,  standing  with  eyes  closed  and  with  the 
feet  close  together,  he  fell  forward  and  to  the  left,  but 
later  he  fell  backward  and  to  the  right.  It  was  found 
on  investigation  that  the  water  used  in  the  left  ear  was 
two  or  three  degrees  colder  than  that  used  in  the  right. 
It  was  quite  some  time  after  the  irrigation  before  the  sub- 
ject could  walk  well.  Some  genuine  attempts  at  vomiting 
were  made  after  the  irrigation,  and  later  when  the  stomach 
tube  was  passed  the  subject  actually  vomited.  This  was 
an  unusual  thing,  for  previously  it  had  been  impossible  to 
upset  the  stomach  by  irrigations.  Evidently  giving  the 
irrigations  with  the  subject  standing  and  making  the  extra 
efforts  necessary  to  preserve  equilibrium,  had  something  to 


218  SEMICIRCULAR   CANALS 

do  with  sickening  the  stomach.  The  chyme  vomited 
amounted  to  5  ^'iii-  It  appeared  to  contain  chiefly  bread 
and  curdled  milk,  the  remains  of  a  meal  of  bread,  butter 
and  milk,  ingested  at  7  a.m.  The  stomach  contents  were 
withdrawn  at  10  a.m.  Analysis  showed:  total  acidity  .32% 
by  weight,  free  HCl  .12%,  combined  HCl  .12%.  There 
was  a  considerable  amount  of  mucus,  but  no  bile  or  blood. 
Starch  and  protein  digestion  was  fair.  Lactic  acid  was 
present,  due  probably  to  the  milk  ingested.  It  should  be 
noted  that  this  was  not  a  regular  test  meal. 

From  the  foregoing,  it  appears  that  by  means  of  hyp- 
notic suggestion  the  disturbances  of  equilibrium  following 
aural  irrigations  can,  to  some  extent,  be  compensated.  It 
is  also  evident,  as  seen  from  protocol  25,  that  in  the  main, 
hypnotic  suggestion  seemed  to  be  able  to  counterbalance 
the  usual  effects  of  aural  irrigations  upon  the  blood- 
pressure.  However,  the  natural  resistance  of  the  indi- 
vidual in  this  respect  must  be  taken  into  consideration, 
since,  on  many  occasions,  irrigations  in  the  normal  waking 
state  were  without  marked  effect  upon  the  circulation.  It 
is  also  fairly  evident  that  hypnotic  suggestion  cannot  alto- 
gether prevent  nystagmus  during  irrigations.  The  effect 
of  posture  upon  the  phenomena  of  nausea  and  vomiting 
was  strikingly  evident  in  this  particular  individual,  who 
could  not  be  made  to  vomit  by  irrigations  or  suggestions 
so  long  as  he  was  allowed  to  remain  sitting,  but  who  was 
easily  sickened  by  irrigations  practised  on  him  whilst 
standing  erect.  It  seemed  that  where  disturbances  of  equi- 
librium were  compensated  by  hypnotic  suggestion  there 
was  subsequently  some  tendency  to  physical  exhaustion.  In 
some  instances  it  was  noted  that  after  repeated  irrigations 
there  was  absence  of  response  on  the  part  of  the  laby- 
rinthine receptors  or  their  related  mechanisms.  This  was 
taken  as  an  indication  of  exhaustion.  A  similar  condition 
was  observed  where  aural  irrigations  and  rotations  were 
practised  simultaneously  or  in  immediate  succession.  It 
should  be  borne  in  mind  that  aural  irrigations  are  not  as 
offectivo  in  producing  labyrinthine  phenomena  as  rotations. 
In  addition  to  this,  the  varying  density,  tliickness,  etc.,  of 
the  portions  of  the  temporal  bone  forming  the  roof  of  the 
external  auditory  canal  and  of  the  tympanum  in  various  in- 


PHYSIOLOGY  219 

dividuals  makes  the  question  of  susceptibility  to  irriga- 
tions a  particular  one  for  each  individual  case.  Hence,  too- 
much  importance  should  not  be  attached  to  h3'pnotic  sug- 
gestion as  a  means  of  counteracting  irrigation  sickoesS;^ 
since  it  had  no  marked  effect  in  offsetting  or  preventing 
the  distressing  effects  of  rotations. 
The  conclusions  are: 

1.  That  in  their  general  effects,  aural  irrigations  act  in 
a  manner  precisely  similar  to  rotations,  causing  identical 
phenomena  by  disturbance  of  the  self-same  organs  and 
mechanisms. 

2.  That  bilateral  simultaneous  stimulation  of  the  laby- 
rinthine receptors  of  moderate  intensity  has  less  effect  in 
causing  the  general  characteristic  nystagmus  and  deviations 
than  unilateral  stimulation  of  the  same  degree,  although 
the  effect  of  both  upon  the  circulation  and  the  mechanism 
of  vomiting  is  about  the  same. 

3.  That  atropin,  adrenalin,  pilocarpin  and  cocain 
(the  last  applied  to  the  external  auditory  canal  and  drum- 
head), have  no  effect  in  preventing  or  suppressing  the  im- 
mediate effects  of  thermic  irritation  of  the  labyrinthine 
receptors  upon  the  cerebellar  and  medullary  centres,  al- 
though some  of  the  remote  secondary  effects  (e.g.,  gastric 
disturbances)  may  be  counterbalanced  by  atropin. 

4.  That  the  characteristic  phenomena  caused  by  aural 
irrigations  are  not  due  to  circulatory  disturbances  in  the 
labyrinth,  such  as  increased  blood-pressure  or  vaso-motor 
disturbances,  because  during  the  height  of  its  action  adren- 
alin did  not  prevent  the  usual  effects  of  aural  irrigations. 

5.  That  hypnotic  suggestion  cannot  overcome  the 
primary  effects  of  vigorous  stimulation  of  the  labyrinthine 
receptors,  though  it  may  help  in  preventing,  for  a  time,, 
displacements  of  equilibrium,  and  offset  the  effects  of 
secondary  disturbances,  such  as  psvchic  distress  and  the 
like. 

6.  That  the  upright  position  (active  equilibration)  has. 
much  to  do  in  determining  certain  of  the  effects,  e.g.,  vom- 
iting, etc.,  of  aural  irrigations,  whilst  the  sitting  posture; 
diminishes  or  delays  them. 


220  SEMICIRCULAR   CANALS 

PROTOCOLS 
18a— On  "S,"  January  10,  1909 

Pulse-  Blood-  Remarks, 

rate,    press. 

68        95      Normal,  sitting. 

72  105 

68  100 

68  105 

68  105 

72  125      On  stimulation  of  retina  by  strong  light. 

76  125 

76  130 

72  105      Light  removed. 

72  105      1  min.  after. 
76        95      2         " 

68  100      3 

72  100      4 
On  second  application  of  the  light  the  blood-pressure  rose 
momentarily,  but  soon  fell  to  90. 

18b— On  «S,"  January  17,  1909 

Normal. 
<  < 

Strong  light  thrown  into  eye 

During  stimulation  of  retina  by  strong  light. 
<(  <<  <<  << 

<<  ft  n  << 

<<  ((  t*  << 

After  removal  of  light. 

<  <  <  < 

it  <  < 

During  stimulation  of  retinae  by  light. 
<<  <<  <<  << 

After  removal  of  light. 

<  <  «< 

18c— On  «S,"  January  10,  1909 

68      115      1  min.  after  irrigation  of  left  ear  at  75°  F. 

for  2  min. 
68      105      2  min.  after  irrigation  of  left  ear  at  75°  F. 

for  2  min. 
68        95      3  min.  after  irrigation  of  left  ear  at  75°  F. 

Dizzy. 
72      100      4  min.  after  irrigation.     Dizziness  gone. 


72 

95 

68 

100 

68 

95 

64 

105 

72 

90 

72 

100 

68 

90 

68 

80 

64 

80 

64 

80 

68 

80 

64 

90 

64 

90 

64 

80 

64 

80 

PHYSIOLOGY 


221 


Time,    Pulse-  Blood- 

a.in.      rate. 

press. 

64 

120 

68 

105 

72 

100 

68 

100 

68 

110 

68 

105 

72 

105 

68 

64 

68 

68 

68 

Remarks. 

Just  after  irrigation  of  right  ear  at  75°  F. 

for  3  min.     Dizzy. 
1  min.  after  irrigation. 
2 
3 

After  irrig'n  of  right  ear  at  115°  F.  for  3  min. 
1  min.  after.     Slight  dizziness. 
2 
After  irrigation  of  right  ear  for  2  min. 

1  min.  after.      No  dizziness  until  now. 

2  "  Dizziness  gone. 
3 

4 


19— On  "S,"  January  24,  1909 


72 

115 

Normal. 

72 

115 

<  < 

72 

120 

Strong  light  in  eyes. 

72 

125 

<  <          <  <           << 

72 

120 

Light  removed. 

72 

120 

1  min.  later. 

72 

110 

Normal. 

72 

110 

( < 

72 

125 

Just  after  cold  irrigation  of  left 

72 

120 

1  min.  later. 

68 

120 

After  cold  irrigation  of  left  ear. 

72 

125 

1  min.  after. 

76 

125 

2 

68 

115 

3 

72 

110 

4 

72 

110 

5 

68 

105 

6 

68 

105 

7 

64 

125 

After  cold  irrigation  of  left  ear. 

72 

125 

1  min.  after. 

76 

120 

2 

68 

115 

3 

72 

110 

4 

68 

115 

5 

68 

110 

6 

64 

115 

After  hot  irrigation  of  left  ear. 

72 

115 

1  min.  after. 

72 

115 

2 

76 

115 

3 

9:38     .. 

Atropin,  gr  1/100,  hypo. 

9:39     72 

105 

72 

110 

72 

100 

68 

105 

222  SEMICIRCULAR   CANALS 

Time,    Pulse-  Blood-  Remarks. 

a.m.      rate,    press. 

9:44  64  110 

68  110 

72  110 

9:48  72  110 

72  100 

64  105 

68   95 

64   95 

64  105 

68  105 

10 :  01     64  120      After  cold  irrigation  of  left  ear. 

64  115      1  min.  after. 

60  105      2 

64  110      3 

68  110      4 

64  110      5 

10:10     64  125      During  hot  irrigation  of  left  ear. 

68  110      1  min.  after. 

68  110      2 

68        95      3 

68  105      4 

64  120      Stimulation  of  left  retina  by  strong  light. 

68  120 

72  115      Light  removed. 

76  110 

76  115      Alternate  stimulation  of  each  retina. 

72  115  "  "   . 

72  115      Light  removed. 
105      1  min.  later. 

About  one  minute  after  the  commencement  of  cold  irri- 
gations the  subject  became  dizzy,  and  external  objects 
seemed  to  move  in  the  horizontal  plane  toward  the  sub- 
ject's right.  This  phenomenon  was  found  to  be  con- 
stant in  all  cold  irrigations  below  a  certain  degree. 
The  dizziness  seemed  to  last  until  the  blood-pressure 
began  to  fall.  After  atropin  the  pulse  was  small  and 
irregular  in  rhythm  and  the  cold  irrigations  seemed  to 
have  greater  power  to  cause  dizziness.  The  hot  irri- 
gations caused  less  dizziness  than  the  cold,  and  the 
apparent  movement  of  external  objects  was  toward 
the  subject's  left,  with  an  up  and  down  element  of 
motion.  All  irrigations  were  given  in  the  left  ear. 
The  subject  was  nauseated  once  during  the  stimula- 
tion of  the  retina  by  strong  light.  After  atropin  the 
cold  irrigations  caused  external  objects  to  move  (ap- 
parently) up  and  down  with  a  wavy  motion  as  well  as 
to  the  subject's  right. 


PHYSIOLOGY 


223 


20a— On  "S,"  January  26,  1909 


Pulse-  Blood- 
rate,     press. 

72   105 


76 
76 
76 
80 
80 
76 


76 
80 
76 
80 
76 
76 


76 
80 
80 
80 
76 
72 
76 
76 
76 
80 
76 
84 
76 


120 
125 
125 
120 
120 
125 


76  125 
76  125 
80   125 


120 
115 
120 
120 
120 
120 


76   120 
76   120 


125 
125 
125 
115 
120 
115 
110 
120 
120 
130 
125 
120 
115 


After  smoking. 


Remarks. 
Respirations  18. 


After  irrigation  of  left  ear  with  warm  water. 

Respirations  18. 
After  irrigation  of  left  ear  with  warm  water. 

Respirations  18. 
After  irrigation  of  left  ear  with  warm  water. 

Respirations  18. 
After  irrigation  of  left  ear  with  warm  water. 

Respirations  18. 


After  irrigation  of  left  ear  with  warm  water. 

Respirations  18. 
After  irrigation  of  left  ear  with  warm  water. 

Respirations  18. 
After  irrigation  of  left  ear  with  warm  water. 

Respirations  18. 
After  cold  irrigation  of  left  ear.  Resp.  24. 


After  hot  irrigation  of  left  ear. 


The  warm  irrigations  had  little  effect  upon  the  blood- 
pressure,  pulse-rate,  or  respiration.  There  was  no 
dizziness  or  nystagmus.  The  subject  experienced 
nothing  but  a  soothing  sensation.  The  cold  irriga- 
tions caused,  at  first,  a  rise  in  blood-pressure  and  in 
the  pulse-rate.  Later  on,  the  blood-pressure  and  pulse- 
rate  fell  and  showed  a  tendency  to  fluctuate.  The 
cold  irrigations,  however,  caused  increased  respira- 
tory rate,  dizziness,  pallor,  nausea,  lump  sensation  in 


224  SEMICIRCULAR   CANALS 

the  stomach  and  nystagmus,  with  apparent  movement 
of  external  objects  to  the  subject's  right.  The  hot 
irrigation  caused  dizziness  and  nystagmus,  but  exter- 
nal objects  seemed  to  move  toward  the  subject's  left. 

20b— On  "S,"  January  29,  1909 


Pulse- 

Blood- 

Remarks. 

rate. 

press. 

76 

115 

Normal. 

80 

110 

<  < 

80 

110 

( < 

76 

115 

After  warm  irrigation  of  right  ear. 

80 

110 

( (             <  <                                <  ( 

80 

115 

« (             ((                                i  < 

^  ^ 

125 

During  cold  irrigation  of  right  ear. 

. 

120 

( (             <  <                               << 

76 

115 

<(             <(                               «( 

80 

120 

1  min.  after. 

80 

120 

2 

80 

120 

3 

76 

120 

4 

The  only  effect  of  the  warm  irrigation  was  a  soothing 
sensation.  The  cold  irrigation  sent  the  blood-pres- 
sure up,  but  there  was  a  marked  immediate  drop  dur- 
ing the  irrigation  not  shown  in  the  blood-pressure 
figures.  In  addition,  there  was  dizziness,  nausea, 
increased  saliva  and  nystagmus,  with  apparent  move- 
ment of  external  objects  toward  the  subject's  left. 
After  the  irrigation  the  subject  had  chilly  sensations 
along  the  spine,  and  felt  as  if  he  "had  swallowed 
smoke."  With  this  there  was  a  sense  of  oppression 
referred  to  the  epigastrium.  The  hearing  for  the 
watch  was  18  inches  for  both  ears.  The  right  exter- 
nal auditory  canal  was  abnormally  tortuous.  The 
persistence  of  the  blood-pressure  at  125  after  the  cold 
irrigation  was  probably  due  to  the  nausea. 


21— On  "B,"  January  31,  1909 
Normal. 


76 

105 

80 

105 

76 

105 

76 

105 

76 

105 

76 

115 

76 

115 

76 

115 

84 

110 

68 

125 

After  cold  irrigation  in  left  ear. 

1  min.  later. 

After  cold  irrigation  of  left  ear. 


PHYSIOLOGY  225 


Time,   Pulse-  Blood-  Remarks. 

a.m.      rate,    press. 

84      120      1  min.  after. 

76      115      2 

After  this  irrigation  there  was  a  slight  dizziness,  es- 
pecially when  the  subject  raised  or  moved  the  head. 
During  the  irrigation  the  subject  began  to  perspire, 
and  a  severe  pain  was  felt  in  the  left  ear. 


72 

125 

After  cold  irrigation  of  left  ear. 

72 

125 

1  min.  after. 

76 

115 

2 

80 

120 

3 

76 

110 

4 

72 

115 

5 

During  the  irrigation  the  subject  experienced  no  dis- 
comfort or  pain.  After  the  irrigation  no  disturbance 
was  felt  so  long  as  the  subject  kept  his  head  still. 
On  raising  the  head,  or  on  looking  up,  the  subject 
became  dizzy  and  external  objects  seemed  to  move 
toward  his  right.  On  rocking  the  head  from  side  to 
side  the  subject  became  sick  and  dizzy  and  experi- 
enced, when  the  head  went  toward  the  left,  a  strange 
sensation  of  dead  weight  on  the  left  side,  so  that  a 
distinct  effort  had  to  be  made  to  drag  the  head  back 
to  the  perpendicular.  After  the  irrigation  the  subject 
felt  weak  and  broke  into  a  general  sweat.  He  had 
the  "lump-sensation"  in  the  stomach  and  felt  very 
depressed  and  wretched.  The  respirations  were  shal- 
low and  of  normal  or  slightly  increased  rate.  The 
subject  evinced  a  marked  inclination  to  lie  down. 

8 :  10  Atropin  crystals,  gr  1/60,  hypo. 

8:38     68  115  Normal. 

64  115 

8 :  40     64  120  After  prolonged  cold  irrigation  of  left  ear. 

68  125  1  min.  after. 

68  120  2 

68  120  3 

67  120  4 

68  115  5 

During  this  irrigation  the  subject  felt  a  pain  extending 
from  the  left  external  auditory  canal  toward  the 
larynx,  and  on  the  next  day  he  developed  a  mild  in- 
flammation in  the  left  tonsil.  After  this  irrigation 
the  dizziness  was  comparatively  slight.  There  was 
no  nausea,  faintness,  or  sweating.  There  was  no 
sense  of  dead  weight  in  the  left  side  of  the  head  when 
the  subject  rocked  his  head  from  side  to  side.  Vision 
was  slightly  disturbed,  but  the  stomach  felt  well  and 
the  irrigation  seemed  to  restore  the  subject's 
strength. 


226  SEMICIRCULAR   CANALS 


22a— On  "S,"  March  7,  1909 

Time,    Pulse-  Blood-  Remarks 

a.m.      rate,  press.  Kemarks. 

68      115  After  bilateral  irrig.  at  115°  F.  for  3  min. 

72  115  During  irrigation  of  left  ear  at  115°  F. 

68  105  After 

68  110  During  bilateral  irrigation  at  100°  F. 

68      105  During  irrigation  of  left  ear  at  100°  F. 

71  110  Normal. 

72  105 
72      105 

68  110  After  ophthalmoscopic  examination. 

60  110  During  bilateral  irrigation  at  70°  F. 

60      105 

72  105  After 

64  115  During  irrigation  of  the  left  ear  at  70°  F. 

68  110  After 


22b— On  "S,"  March  28,  1909 

68       ...       After  irrigation  of  left  ear  at  61°  F. 
Atropin  crystals,  gr  1/45,  hypo. 


10: 

:42 

10: 

:48 

60 

110 

10: 

:49 

52 

105 

10: 

:50 

56 

105 

10: 

:59 

64 

100 

11: 

:00 

60 

110 

11: 

:06 

72 

125 

11: 

:12 

80 

120 

11: 

;13 

80 

125 

11: 

:14 

76 

120 

11: 

:15 

84 

130 

84 

100 

84 

105 

84 

110 

80 

115 

11: 

:32 

80 

120 

11: 

:33 

135 

140 

80 

During  irrig.  of  left  ear  at  61°  F.  for  2  min. 


Normal. 

During  irrig.  of  left  ear  at  61°  F.  for  2  min. 


125  "  "  " 

76      115      2  min.  after  irrig.  of  left  ear  at  61°  F.  for  2 
min. 
105      3  min.  after  irrigation  of  left  ear. 


22c— On  "S,"  April  2,  1909 

10 :  42      . .         . .      Atropin  crystals,  gr  1/45,  hypo. 
9:30     60      115      Normal. 
10  :  41     68      125      Hasty  news  of  wife's  illness. 


Time,   Pulse- 

Blood- 

a.m.      rate. 

press. 

.0:43     72 

165 

120 

56 

115 

68 

125 

68 

125 

68 

120 

60 

125 

PHYSIOLOGY  227 


Remarks. 

During  irrigation  of  left  ear  at  60°  F. 

After 

Before  bilateral  irrigation  at  55°  F. 

30  sec.  after      " 

60 

After  bilateral  irrigation  at  115°  F. 

After  irrigation  of  left  ear  at  115°  F. 


23a— On  "S,"  April  9,  1909 

64  110  Normal,  sitting. 

64  110 

60  115  Lying  supine. 

60  115 

64  130  During  irrigation  of  left  ear  at  65°  F. 

64  135 

64  125  After      " 

64  115 

64  135  During  bilateral  irrigation  at  65°  F. 

60  115  Before  irrigation  of  left  ear  at  110°  F. 

64  125  During 

60  110  Before  bilateral  irrigation  at  110°  F. 

60  120  During 

60  120  During  irrigation  of  left  ear  at  115°  F. 

60  110  Before  irrigation  of  left  ear  at  65°  F. 

60  110  During 

68  120  "  "  **    Before  vomiting. 

..  135  "  "  "    After  vomiting. 


23b— On  "S,"  April  16,  1909 
Normal  before  irrigation. 


68 

100 

68 

100 

68 

105 

68 

110 

68 

110 

During  irrig.  of  left  ear  at  101°  F.  under 

pressure  of  a  few  inches. 
72      110      During  irrig.  of  left  ear  at  101°  F.  under 

pressure  of  a  few  inches. 
68      110      During  irrig.  of  left  ear  at  101°  F.  under 

pressure  of  a  few  inches. 
72      110      During  irrig.  of  left  ear  at  101°  F.  under 

pressure  of  a  few  inches. 
72      110      During  irrig.  of  left  ear  at  101°  F.   under 

pressure  of  a  few  inches. 
72      115      During  irrig.  of  left  ear  at  101°  F.   under 

pressure  of  a  few  inches. 
68      110      After   irrig.   of   left  ear  at  101°  F.  under 

pressure  of  a  few  inches. 


228  SEMICIRCULAR   CANALS 


Time,    Pulse-  Blood-  Remarks 

a.m.      rate,    press.  Kemarks. 

72      100      After  irrig.  of   left   ear   at   101°  F.    under 

pressure  of  a  few  inches. 
68      100      After   irrig.  of   left   ear   at   101°  F.  under 

pressure  of  a  few  inches. 
76      100      Normal  before  irrigation. 
72      100 
72      100 
68      120      During   irrig.   of  left  ear   at  101°  F.  under 

pressure  of  4|  feet. 
68      130      During  irrig.  of  left  ear  at  101°  F.  under 

pressure  of  4f  feet. 
72      130      During  irrig.  of  left  ear  at  101°  F.  under 

pressure  of  4|  feet. 
64      105      After  irrig.  of  left  ear  at   101°   F.   under 

pressure  of  4|  feet. 
64      100      After  irrig.  of  left  ear  at  101°  F.   under 

pressure  of  4|  feet. 
60      100      After  irrig.  of  left  ear  at  101°  F.   under 

pressure  of  4|  feet. 
60      100      After  irrig.    of  left  ear  at  101°  F.  under 

pressure  of  4|  feet. 
64      100      After  irrig.  of  left  ear  at  101°   F.    under 

pressure  of  4|  feet. 


23c— On  «S,"  April  23,  1909 

10:02     64      105      Normal. 

64      105 

64      105 
10:04  Adrenalin     chloride    minims    ii     intraven- 

ously. 
10 :  04i   56      130      Injection  faulty.     Much  of  drug  lost. 
10 :  05     56      105 
10 :  06     60      105 
10:09     60      105      Normal. 

10 :  10  Adrenalin     chloride    minims    iii    intraven- 

ously. 
170      After  adrenalin. 

..       170 

..       160 
10:18     64      100 


24— On  "S,"  June  20,  1909 
3:42     68      100      Normal,  lying  supine. 


68 

100 

64 

105 

64 

105 

64 

105 

64 

105 

PHYSIOLOGY  229 


Time.    Pulse- Blood-  Remarks, 

a.m.      rate,  press. 

68  100      Normal,  lying  supine. 

68  100 
4:00  Pilocarpin  hydrochloride  gr  16,  hypo. 

4 :  02     76        95      Saliva  profuse.     Fulness  in  head. 

4 :  03     76  100      Radial  artery  large. 

76  100 

80  105 

80  105 

80  100 

4 :  07     80  110      Radial  artery  smaller.    Forehead  moist. 

84  110      Pains  in  glans  penis,  as  if  he  wants  to  urinate. 

80  110 

80  115 

80  105 

84  105 

84  110 

4 :  15     80  110      Forehead  covered  with  sweat. 

80  120 

4 :  19     76  125      Cooled  sweat  ran  into  ear  canal. 

76  120 

84  115 

84  120 

84  120 

4 :  24     76  115      Sweat  and  saliva  profuse. 
4 :  25  Irrigation  of  left  ear  at  68°  F.     The  irriga- 

tion   caused    nystagmus    and    the    usual 
symptoms. 

4 :  25     76  125      During  irrigation  of  left  ear  at  68°  F. 

76  125 

76  120 

4 :  29     76  120      After  irrigation  of  left  ear  at  68°  F. 

80  115 

76  115 

72  115      Feels  sick.    On  the  verge  of  vomiting. 

72  100 

76  105 

72  105 

4 :  39     76  105      Pain  has  left  penis. 

76  105 

72  105 

72  105 

68  105 

4:45     72  110      During   irrig.   of  left  ear  at  115°  F.     The 
usual  phenomena  appeared. 

76  115      During   irrig.    of  left  ear   at  115°  F.     The 
usual  phenomena  appeared. 

72  115      During  irrig.    of   left  ear  at  115°  F.     The 
usual  phenomena  appeared. 

68  105      After  irrig.  of  left  ear  at  115°  F.     The  usual 
phenomena  appeared. 


230 


SEMICIRCULAR  CANALB 


Time,    Pulse-  Blood- 
a.ni.      rate,    press. 

68   105 


4:53  72 
72 
72 
68 
12 
68 
68 
64 
68 

5 : 06  68 

64 
68 
64 


5:15 


68 
64 
64 
64 
60 
5:23  60 
64 


95 
100 
105 
110 
115 
110 
110 
115 
105 
110 

115 
110 
105 


64  95 

60  100 

64  105 

68  110 


105 
105 
110 
105 
110 
105 
105 


Remarks. 

After  irrig.  of  left  ear  at  115°  F.     The  usual 

phenomena  appeared. 
Feels  sick.     Distressed  in  stomach. 


Forehead  dry. 


During  irrig.  of  left  ear  at  115°  F.    Usual 
phenomena. 


After  irrig.  of  left  ear  at  115°  F.     Usual 

phenomena. 
After  irrig.  of  left  ear  at  115°  F.     Usual 

phenomena. 
After  irrig.  of  left  ear  at  115°  F.     Usual 

phenomena. 
After  irrig.  of  left  ear  at  115°  F.     Usual 

phenomena. 
After  irrig.  of  left  ear  at  115°  F.    Usual 

phenomena. 
Resting. 


Pain  referred  to  left  of  epigastrium. 


Pilocarpin  did  not  prevent  the  occurrence  of  the  usual 
phenomena  that  attend  aural  irrigations,  viz.  :  ver- 
tigo, nystagmus,  nausea,  etc.  After  the  administra- 
tion of  the  drug  the  pulse-rate  and  blood-pressure 
showed  a  tendency  to  rise,  followed  by  a  gradual  sub- 
sidence to  the  normal.  The  irrigations  affected  the 
pulse-rate  and  blood-pressure  much  as  they  do  where 
no  drug  has  been  previously  administered,  i.e.,  the 
blood-pressure  was  raised  at  first  and  later  on  low- 
ered, the  pulse-rate  at  first  being  lowered  somewhat 
and  later  slightly  raised. 


60  120 
72  120 
72   115 


25-On  "F,"  Sept.  22,  1909 
Normal. 


84 

115 

84 

115 

88 

115 

88 

110 

76 

115 

76 

115 

84 

120 

88 

115 

PHYSIOLOGY  231 


Pulse-  Blood-  Remarks, 

rate,    press. 

68      120      During  irrig.  of  left  ear  at    68°  F.  without 

hypnosis. 
68      120     During  irrig.  of  left  ear  at  68°  F.  without 

hypnosis. 
68      115      Resting  under  waking  hypnosis. 

An  irrigation  in  the  left  ear  at  69°  F. ,  under 

hypnosis  and  with  the  suggestion  that  the 

water  was  tepid,  caused  no  distress  and 

did  not  alter  the  blood-pressure. 
68      115      During  irrig.  at  69°  F.  with  suggestion  that 

it  was  tepid  water. 
64      115      During  irrig.  at  69°  F. ,  with  suggestion  that 

it  was  tepid  water. 
64      115      During  irrig.  a  69°  F.,  with  suggestion  that 

it  was  tepid  water. 
Normal. 


Resting  under  hypnosis. 


Under  hypnosis  an  irrigation  at  115°  F.  was 
given  in  the  left  ear,  with  the  suggestion 
that  it  was  tepid  water. 

76      110      During   irrig.    at   115°  F.,  with  suggestion 

water  was  tepid. 
80      100      During   irrig.    at   115°   F.  with    suggestion 

water  was  tepid. 
80      110      During   irrig.    at   115°  F.,  with    suggestion 

water  was  tepid. 
88      105      During   irrig,    at  115°   F.,  with  suggestion 

water  was  tepid. 

An  irrigation  was  given  in  the  left  ear  at  120°  F.  under 
hypnosis,  with  the  suggestion  that  the  water  was 
tepid.  The  irrigation  caused  a  rise  in  blood-pressure 
and  pulse-rate,  but  the  subject  manifested  no  signs 
of  nausea  or  sickness  until  it  was  suggested  to  him 
that  the  irrigation  was  making  him  sick,  when  he 
began  to  make  forced  attempts  at  vomiting,  but  no 
actual  vomiting  occurred. 

84      110      During   irrig.  at  120°   F.,  with   suggestion 

that  the  water  was  tepid. 
92      130      During  irrig.  at    120°  F.,    with   suggestion 

that  the  water  was  tepid. 
92      135      During   irrig.  at   120°  F.,  with   suggestion 

that  the  water  was  tepid. 


282  SEMICIRCULAR   CANALS 


!s?e!-  fS:  R— =- 


84      125      During   irrig.  at   120°  F.,  with   suggestion 
that  the  water  was  tepid. 

An  irrigation  was  given  in  the  left  ear  at  64°  F.  under 
hypnosis,  and  with  the  suggestion  that  the  irrigation 
would  cause  sickness  and  vomiting.  Many  attempts 
were  made,  but  no  actual  vomiting  occurred.  In  later 
tests  vomiting  was  brought  on  by  irrigations  prac- 
tised with  the  subject  standing. 

76      115      During  irrig.  at  64°  F.,  with  suggestion  that 

it  would  sicken. 
84      125      During  irrig.  at  46°  F.    with  suggestion  that 

it  would  sicken. 
84      125      During  irrig.  at  64°  F.,  with  suggestion  that 

it  would  sicken. 
96      130      During  irrig.  at  64°  F.,  with  suggestion  that 

it  would  sicken. 
88      115      After  irrig.  at  64°  F.,  with  suggestion  that 

it  would  sicken. 
84      115     After  irrig.  at  64°  F.,  with  suggestion  that 

it  would  sicken. 
84      115      After  irrig.  at  64°  F.,  with  suggestion  that 

it  would  sicken. 
84      115      After  irrig.  at  64°  F. ,  with  suggestion  that 

it  would  sicken. 
84      115      After  irrig.  at  64°  F. ,  with  suggestion  that 

it  would  sicken. 
92      110      After  irrig.  at  64°  F.,  with  suggestion  that 

it  would  sicken. 
92      105      After  irrig.  at  64°  F.,  with  suggestion  that 

it  would  sicken. 


CHAPTER  XVI 

THE   EFFECTS   OF  AURAL    IRRIGATIONS   UPON  THE 
DIGESTIVE   APPARATUS 

Aural  irrigations  affect  the  stomach  functions  precisely 
as  do  rotations.  Depending  on  the  degree  of  irritation  of 
the  labyrinthine  receptors,  which  in  turn  depends  upon  the 
variation  from  the  neutral  limits  of  the  temperature  of 
the  fluid  used,  vertigo,  nausea,  increased  salivation,  ab- 
normal sensations  referred  to  the  stomach,  stasis  of  food 
content,  failure  of  absorption,  and  vomiting  are  readily 
caused  in  rapid  succession.  Marked  congestion  also  oc- 
curs, as  evidenced  by  the  vomiting  of  blood  on  a  few  occa- 
sions. It  was  a  noticeable  feature  of  aural  irrigations  and 
rotations  that  vomiting  occurred  with  little  warning  and 
was  of  the  projectile  type.  This  made  it  necessary  to  in- 
terrupt the  irrigations  from  time  to  time  so  that  the  test 
meal  should  be  retained  the  proper  length  of  time.  In 
the  following  tests,  after  irrigating  the  stomach,  the  regu- 
lar Ewald  meal  was  given  and  allowed  to  remain  in  the 
stomach  for  one  hour  during  which  irrigations  were  given 
as  frequently  as  the  subject  could  tolerate  them  without 
vomiting.  The  amount  of  chyme  removed  after  cold  irri- 
gations with  the  subject  sitting  upright  averaged,  in  three 
test  meals,  §xiii.  With  the  subject  lying  down,  the 
amount  of  chyme  removed  was  jviii  in  one  test  meal.  In 
a  control  test  meal  in  which  no  irrigations  were  given, 
the  amount  of  chyme  removed  after  one  hour  was  3iv. 

In  cold  irrigations,  with  the  subject  sitting  upright,  the 
K  I  absorption  test  showed  the  presence  of  iodin  in  the 
saliva  in  32  minutes  upon  the  average.  In  bilateral  irriga- 
tions (one  test  meal) ,  with  the  subject  sitting  upright,  there 
was  no  reaction  at  any  time  for  iodin  in  the  saliva  al- 
though the  latter  was  much  increased.  In  cold  irrigations, 
with  the  subject  lying  supine,  the  saliva  failed  to  show  the 

233 


234  SEMICIRCULAR  CANALS 

presence  of  iodin  all  through  the  irrigations.  In  these 
irrigations  the  saliva  was  not  increased.  In  a  control 
test  meal,  the  saliva  reacted  for  iodin  in  19  minutes. 
The  apparent  difference  between  the  results  of  the  absorp- 
tion tests  in  aural  irrigations  with  the  subject  sitting  erect 
and  in  rotations  may  be  partly  explained  perhaps,  by  the 
fact  that  frequent  intervals  of  rest  had  to  be  allowed  be- 
tween irrigations  whereas  in  rotations  about  the  long  axis 
the  movements  were  constant  though  mild.  However,  the 
fact  seems  also  to  emphasize  the  greater  efficiency  of  rota- 
tion in  perverting  gastric  function.  Where  irrigations 
were  prolonged,  as  in  irrigations  in  recumbency,  or  where 
the  degree  of  irritation  was  intense,  as  in  bilateral  irriga- 
tions, the  tests  failed  to  show  any  evidence  of  absorption. 

The  salol  test  for  stomach  motility  showed  that  at  no 
time,  before  or  after  the  irrigations,  was  there  any  evi- 
dence that  stomach  contents  had  escaped  into  the  intestine. 
However,  a  control  test  meal  showed  the  presence  of  salol 
in  the  intestine  in  2  hours  and  32  minutes.  In  this  test 
however,  the  salol  had  been  given  just  after  the  meal. 
Given  in  this  way  it  is  quite  possible  that  most  of  the 
food  might  reach  the  intestines  before  the  salol.  Griitz- 
ner  ^^  has  shown  by  feeding  rats  at  different  times  with  food 
of  different  colours,  that  the  food  first  ingested  lay  next 
to  the  stomach  walls,  whilst  the  succeeding  portions  were 
arranged  in  regular  concentric  fashion.  In  this  way  most 
of  the  food  first  taken  might  reach  the  intestine,  whilst 
part  of  it  might  find  its  way  to  the  fundus  and  reach  the 
intestine  with,  or  perhaps  after,  food  ingested  at  a  later 
.time. 

From  this  it  is  evident  that  for  purposes  of  testing  gas- 
tric motility  salol  should  be  administered  at  the  com- 
mencement, and  not  at  the  end,  of  the  test  meal.  In  the 
tests  for  stasis  of  gastric  food  content,  failure  of  intes- 
tinal absorption  might  also  be  a  possible  source  of  error. 
In  the  experiments  where  the  salol  test  showed  no  reaction 
for  the  presence  of  salicyluric  acid  in  the  urine,  definite 
direct  proof  of  excluding  the  failure  of  intestinal  absorp- 
tion is  wanting.  It  was  deduced,  however,  from  general 
considerations,  and  especially  from  the  fact  that  whenever 
there  was  evidence  of  propulsion  of  food  into  the  intes- 
tine there  was  also  evidence  of  active  absorption,  whereas 


PHYSIOLOGY  235 

on  frequent  occasions  absorption  was  fairly  active  and  yet 
everything  pointed  to  complete  stasis  of  the  gastric  food 
content. 

In  cold  unilateral  irrigations,  with  the  subject  sitting 
upright,  the  average  in  two  test  meals  showed:  total 
acidity  .18%  by  weight;  free  HCl  .11%,  and  combined 
HCl  .05%.  In  one  test  meal  the  figures  were:  total 
acidity  .  18,  free  HCl  absent,  combined  HCl  .09.  This 
was  the  occasion  on  which  the  subject  vomited  gross  blood, 
evidence  of  which  was  also  found  in  the  chyme  taken 
through  the  tube. 

In  cold  bilateral  irrigations,  with  the  subject  sitting 
upright,  the  total  acidity  was  .14,  the  free  HCl  .09,  and 
the  combined  HCl  .05  (one  test  meal).  In  this  instance 
the  K  I  test  failed  to  show  iodin  in  the  saliva  which  was 
abundant. 

In  cold  irrigations,  with  the  subject  lying  supine,  the 
total  acidity  was  .14,  the  free  HCl  .09,  and  the  combined 
HCl  .03.  The  saliva  was  not  increased  and  did  not  re- 
act for  iodin. 

In  a  control  test  meal  the  figures  were :  total  acidity, 
.26,  free  HCl  .16,  combined  HCl  .08. 

In  three  meals  consisting  of  bread,  butter  and  tea, 
with  milk  and  sugar,  and  allowed  to  remain  in  the  stomach 
upon  an  average  of  one  hour  and  28  minutes  the  average 
amount  of  chyme  removed  was  |iii.  The  average  of  the 
analyses  showed:  total  acidity  .26,  free  HCl  .19,  com- 
bined HCl  .05. 

In  one  meal,  consisting  of  beefsteak,  potatoes,  bread, 
butter,  cocoa  with  milk  and  sugar,  and  allowed  to  remain 
in  the  stomach  3 J  hours,  the  amount  of  ch}Tne  removed 
was  |iiiss.  The  figures  were:  total  acidity  .52,  free 
HCl  .28,  combined  HCl  .16. 

From  the  foregoing  it  is  manifest  that  the  pylorus  is 
tightly  closed  in  aural  irrigations,  except  perhaps  where 
they  were  practised  with  the  subject  in  the  supine  posture 
when  the  salol  test  was  not  tried.  General  experience 
however,  seems  to  show  that  even  in  such  irrigations  when 
they  are  prolonged,  or  of  such  a  temperature  as  to  beget  a 
high  degree  of  thermic  irritation,  the  pylorus  permits 
nothing  to  escape  into  the  intestine.  Since  the  foregoing 
was  written  this  matter  has  been  fuUy  tried  out.     It  was 


236  SEMICIRCULAR   CANALS 

found  that  nothing  escaped  into  the  intestine  when  the 
irrigations  were  kept  up  fairly  constantly  and  that  absorp- 
tion was  retarded  and  the  saliva  diminished  or  not 
increased. 

It  is  also  manifest  that  in  all  aural  irrigations  the 
stomach  acidity  is  relatively  diminished.  Where  the 
amount  of  chyme  and  the  saliva  were  increased,  and  the 
salol  test  negative,  it  is  a  question  whether  the  diminished 
acidity  was  not  due  in  part  to  increased  salivary  content. 
In  a  special  test,  the  subject  was  instructed  not  to  swallow 
any  saliva  during  the  irrigations.  The  result  nevertheless 
was  the  same  as  regards  lowered  acidity,  although  there 
was  a  diminution  in  the  amount  of  ch}rme. 

With  irrigations  in  the  supine  posture,  the  acidity  was 
absolutely  diminished.  This  points  to  a  diminished  pro- 
duction of  acid,  since  in  this  instance,  as  in  rotations 
with  the  subject  lying  supine,  the  saliva  was  not  increased. 
At  all  events  whatever  the  cause,  for  all  practical  purposes 
of  digestion  the  acidity  was  reduced. 

In  irrigations  with  the  subject  sitting  upright,  absorp- 
tion from  the  stomach  was  slightly  delayed,  whilst  in  bi- 
lateral irrigations  with  the  subject  sitting  upright  the 
saliva,  though  increased,  did  not  at  all  react  for  iodin. 
This  shows  that  increased  stimulation  completely  inhibits 
absorption  and  perhaps  stimulates  the  pylorus  to  a  more 
tonic  state  of  contraction. 

The  diminished  salivation  observed  in  irrigations  in 
the  supine  posture  is  explained  by  the  diminished  activity 
of  the  otolithic  apparatus  in  decubitus  whereby  fewer  tonus 
impulses  are  sent  from  the  labyrinth  to  the  nausea  and 
vomiting  mechanisms  and  the  closely  related  centre  for 
salivary  secretion  in  the  medulla.  The  negative  reaction 
of  the  K  I  absorption  test  may  perhaps  be  attributed  to 
the  failure  of  salivary  secretion,  but  this  does  not  at  all 
seem  probable.  In  a  later  test,  absorption  was  distinctly 
retarded. 

The  conclusions  are: 

1.  That  aural  irrigations  affect  the  digestive  apparatus 
as  do  rotations  and  act  upon  the  self-same  mechanisms. 

2.  That,  as  in  rotations,  dorsal  decubitus  tends  to  pre- 
vent nausea,  increased  salivation  and  vomiting  with  the 
attendant  psychic  distress,  but  does  not  prevent  the  imme- 


PHYSIOLOGY  287 

diate  effects  of  labyrinthine  irritation  or  depression  upon 
the  medullary  and  cerebellar  centres  whereby  vertigo,  nys- 
tagmus, closure  of  the  pylorus,  inhibition  of  normal  gas- 
tric secretion,  etc. ,  are  produced. 

The  Effects  of  Aural  Irrigations   Upon  Equilihration 

With  the  subject  sitting  upright  a  cold  irrigation  in 
the  left  ear  at  70°  F.  if  continued  for  a  time  varying  from 
2  to  4  minutes,  will  cause  lateral  inclination  of  the  head 
toward  the  left  shoulder  and  horizontal  nystagmus  directed 
toward  the  right  with  a  subsidiary  rotary  element  against 
the  watch.  If  the  subject  keep  the  eyes  closed  during 
the  irrigation,  he  will  experience  a  sense  of  rotation 
about  the  long  axis  of  his  body  from  left  to  right. 
When  the  nystagmus  is  fully  developed,  external  objects 
appear  to  move  steadily  from  left  to  right  with  a  slight 
tendency  downward.  After  the  irrigation,  if  the  subject 
attempt  to  walk  he  will  deviate  toward  the  left,  though  after 
a  time  it  is  common  to  have  a  period  when  he  may  devi- 
ate toward  the  right.  This  is  a  reactionary  stage  corre- 
sponding to  the  after-nystagmus  that  occurs  in  rotations. 
With  the  inclination  of  the  head  toward  the  left,  is  experi- 
enced a  sense  of  lightness  or  emptiness  in  the  right  side 
of  the  head  and  scalp,  and  a  corresponding  sense  of  dead 
weight  and  heaviness  in  the  left  side.  After  the  irriga- 
tion, as  the  vertigo  and  nystagmus  subside  they  can  be 
revived  by  tilting  the  head  from  side  to  side,  or  by  turn- 
ing the  eyes  strongly  upward  or  to  the  side  to  which  the 
nystagmus  was  directed. 

The  effects  of  cold  irrigations  of  the  left  ear  can  be 
readily  recognized  as  similar  in  every  respect  to  the  pri- 
mary effects  of  rotation  about  the  long  axis  of  the  body 
from  left  to  right. 

In  an  irrigation  at  115°  or  120°  F.  given  in  the  left  ear, 
similar  phenomena  will  be  observed,  only  in  this  instance 
the  lateral  inclination  of  the  head  will  be  toward  the  right 
and  the  horizontal  nystagmus  directed  toward  the  left 
with  a  rotary  element  with  the  watch,  whilst  external  ob- 
jects will  appear  to  move  from  right  to  left  and  wdth  a 
slight  tendency  downward. 

The  effects  of  hot  irrigations  of  the  left  ear  are  thus 


238  SEMICIRCULAR  CANALS 

seen  to  be  identical  with  the  primary  effects  of  rotations 
about  the  long  axis  from  right  to  left. 

If  a  bilateral  irrigation  at  71°  F.  be  given  for  from  2 
to  4  minutes  to  a  normal  person  sitting  erect,  and  if  care 
be  taken  to  see  that  the  temperature  of  the  water  used  is 
the  same  on  both  sides,  and  that  the  fluid  enters  the  audi- 
tory canal  under  equal  pressure  on  either  side,  there  will 
be  no  horizontal  nystagmus  or  marked  deviation  of  the 
head  or  eyes  to  one  side  more  than  the  other,  though  the 
head  on  tilting  may  feel  rather  heavy  on  either  side. 
There  will,  however,  be  a  steady  pull  of  the  head  forward 
on  the  chest,  and  external  objects  will  appear  to  move  up 
and  down  or  away  from  the  subject  in  the  mesial  plane. 
With  these  will  be  found  a  mild  degree  of  vertical  nystag- 
mus of  short  range  and  directed  toward  the  top  of  the 
head.  During  a  bilateral  irrigation  at  71°  F.  with  the  sub- 
ject in  the  supine  posture  and  with  the  eyes  open,  the 
subject  felt  as  if  the  couch  were  falling  away  from  his 
body,  i.e.,  as  if  he  were  rotating  in  the  mesial  plane  "oc- 
ciput first. ' '  If  the  eyes  be  closed  when  the  nystagmus 
is  in  full  activity,  the  subject  will  feel  his  body  moving 
up  and  down  in  the  mesial  plane  "see-saw  fashion." 
During  the  nystagmus,  turning  the  opened  eyes  strongly  to 
one  side  or  the  other  may  develop  a  horizontal  nystagmus 
with  a  rotary  element.  Turning  the  eyes  up  toward  the 
vertex  also  seems  to  aggravate  the  vertical  nystagmus 
toward  the  top  of  the  head.  The  study  of  nystagmus  in 
the  irrigations  under  consideration  is  a  matter  of  some 
difficulty  and  it  is  only  after  repeated  trials  in  various 
postures  that  one  can  convince  himself  of  the  true  direc- 
tion of  the  ocular  movements. 

The  general  effects  of  cold  bilateral  irrigations  resemble 
the  primary  effects  of  rotations  in  the  mesial  plane  ' '  occi- 
put first' '  or  the  secondary  effects  of  rotations  in  the  mesial 
plane  "face  first."  It  will  be  remembered  that  in  rota- 
tions in  the  mesial  plane  "face  first"  the  after  nystagmus 
was  of  short  range  and  duration,  and  its  direction  diffi- 
cult to  ascertain. 

Bilateral  irrigations  at  115  to  120°  F.  cause  vertical 
nystagmus  directed  toward  the  feet.  Objects  seem  to  be 
moving  from  the  head  toward  the  feet  in  the  mesial  plane. 
The  effects  of  these  irrigations  resemble  the  primary  effects 


PHYSIOLOGY  ^B9 

of  rotations  in  the  mesial  plane  ' '  face  first' '  or  the  second- 
ary effects  of  rotations  in  the  mesial  plane  ' '  occiput  first. ' ' 

With  the  subject  on  the  back  and  the  head  lowered  so 
as  to  make  an  angle  of  35°  between  the  long  axis  of  the 
body  and  the  horizon,  irrigations  of  the  left  ear  gave  the 
usual  phenomena  that  accompany  similar  irrigations  in 
the  supine  j)osture  with  the  body  in  the  horizontal  plane. 

Irrigations  of  the  left  ear  at  71°  F.  with  the  subject 
lying  on  the  left  side  caused  the  usual  horizontal  nystag- 
mus toward  the  right  with  objects  appearing  to  move  in 
the  same  direction.  If  during  the  irrigation  the  closed 
eyes  were  directed,  as  though  looking  at  an  object  straight 
in  front  of  the  face,  the  subject  felt  his  body  moving  back 
and  forth  in  the  mesial  plane,  but  the  head  at  all  times 
seemed  to  be  lower  than  the  feet.  With  the  closed  eyes 
directed  to  the  left,  the  subject  felt  his  body  revolving  in  the 
mesial  plane  face  forward.  With  the  closed  eyes  directed 
to  the  right  he  felt  his  body  revolving  about  its  long  axis 
from  left  to  right.  These  phenomena  show  that  turning 
the  eyes  strongly  to  one  side  or  the  other  not  only  inhibits 
or  enhances  the  movements  of  the  characteristic  nystag- 
mus, but  in  the  case  of  inhibition  of  the  typical  form 
tends  to  develop  a  latent  vertical  nystagmus.  Thus  turn- 
ing the  eyes  to  the  right  evidently  exaggerated  the  hori- 
zontal nystagmus  to  the  right  which  it  is  well  known  it 
always  does,  and  the  subject  felt  his  body  rotating  about 
its  long  axis  from  left  to  right.  Voluntarily  fixing  the 
eyes  in  front,  tends  also  to  inhibit  the  horizontal  element 
directed  to  the  right  and  partially  develops  the  latent 
vertical  nystagmus  with  its  associated  sense  of  motion  of 
the  head  and  feet  backward  and  forward  in  the  mesial 
plane.  Turning  the  eyes  strongly  to  the  left  completely 
inhibits  the  lateral  horizontal  element  directed  to  the  right, 
whilst  it  allows  the  latent  vertical  element  free  play  which 
in  this  instance  Avas  directed  toward  the  feet  evoking  the 
associated  sense  of  motion  of  the  body  "face  first"  in  the 
mesial  plane.  The  causation  of  these  phenomena  w^ill  be 
discussed  in  a  later  chapter. 

In  irrigations  of  the  left  ear  at  117°  F  with  the  subject 
lying  on  the  left  side,  objects  seemed  to  move  from  the  feet 
toward  the  head  with  a  slight  deviation  toward  the  right. 
With  eyes  closed  and  directed  straight  ahead,  the  subject 


240  SEMICIRCULAR  CANALS 

felt  his  body  revolving  about  its  long  axis  from  right  to 
left.  With  the  closed  eyes  directed  to  the  left,  he  felt 
himself  revolving  about  the  long  axis  of  his  body  from 
right  to  left.  With  the  closed  eyes  directed  to  the  right, 
he  felt  his  body  revolving  in  the  mesial  plane  "occiput 
first."  After  the  irrigation  external  objects  seemed  to 
move  about  his  body  and  in  front  of  his  face  over  his  head 
in  the  direction  of  the  hands  of  the  watch,  i.e.,  in  the 
coronal  plane.  Here  again  is  evidence  of  the  simultaneous 
presence  of  three  forms  of  nystagmus,  viz. ,  vertical,  hori- 
zontal, and  rotary,  any  one  of  which  may  be  enhanced  at 
the  expense  of  the  other  two  by  turning  the  eyes  in  the 
direction  calculated  to  favor  it.  The  fact  that  at  the  on- 
set of  the  irrigation,  external  objects  appeared  to  move 
from  the  feet  toward  the  head  is  to  be  attributed  to  volun- 
tary fixation  inhibiting  the  horizontal,  but  not  affecting 
the  rotary  nystagmus.  Risien-Russell  ^^  found,  after  ex- 
clusion of  the  lateral  movements  of  the  eyes,  that  the  only 
other  movements  represented  in  the  frontal  ocular  areas 
of  the  dog  and  cat  were  the  upward  movements.  It  seems 
therefore  that  these  animals,  and  perhaps  those  higher  in 
the  scale,  have  power  to  inhibit  voluntarily  side  to  side 
movements  of  the  eyes  and  vertical  movements  directed 
from  above  downward,  whilst  the  power  to  inhibit  volun- 
tarily other  ocular  reflex  movements  is  wanting.  There  is 
evidence  that  in  man  the  power  of  voluntary  control  of  up- 
ward vertical,  and  of  rotary  movements  of  the  eyes  is  less 
than  in  the  case  of  the  other  movements. 

This  is  evidenced  by  the  fact  that  in  most  forms  of 
vertigo,  straining  the  eyes  upward  tends  to  aggravate  the 
distress,  whilst  few  if  any  have  the  power  of  turning  the 
eyes  voluntarily  upon  the  horizontal  antero-posterior  axis. 

It  is  also  in  part  due  to  the  feebleness  of  voluntary  con- 
trol of  the  upward  movements  of  the  eyes  that  rotation  in 
the  mesial  plane  with  the  "occiput  first"  causes  such 
furious  primary  nystagmus  and  distress,  whereas  rotations 
in  the  same  plane  with  the  "face  first"  cause  but  little 
nystagmus  or  distress. 

Irrigation  of  the  left  ear  at  72°  F.  for  6  minutes,  with 
the  subject  lying  suj^ine,  caused  the  usual  mixed  nystag- 
mus, with  the  horizontal  element  directed  to  the  right,  and 
the  rotary  element  against  the  watch.    With  the  eyes  turned 


PHYSIOLOGY  241 

to  the  left  during  the  irrigation,  external  objects  seemed 
to  move  from  the  floor  to  the  ceiling,  i.e.,  in  the  mesial 
plane  from  behind  forward.  On  looking  straight  ahead, 
objects  seemed  to  move  from  left  to  right  in  a  plane  at 
right  angles  to  the  long  axis  of  the  body.  On  looking  to 
the  right,  objects  seemed  to  move  from  head  to  foot  with 
a  wheel-like  motion  in  the  coronal  plane,  i.e.,  against 
the  watch. 

When  the  eyes  were  closed  and  allowed  to  assume  any 
position,  the  subject  felt  his  body  rotating  in  the  coronal 
plane  against  the  watch  with  an  added  slight  up  and  down 
motion  of  the  head  and  feet  in  the  mesial  plane,  and  a 
feeling  that  the  head  was  lower  than  the  feet.  Every  in- 
spiration seemed  to  influence  this  up  and  down  motion  of 
the  body.  With  eyes  closed  and  turned  to  the  left,  the 
subject  felt  his  body  rotating  in  the  coronal  plane  with 
the  watch.  He  felt  also  a  slight  sense  of  rotation  about 
the  long  axis  from  right  to  left,  and  his  head  seemed  to 
be  lower  than  his  feet.  With  eyes  closed  and  directed 
straight  ahead,  he  felt  his  body  rotating  in  the  coronal 
plane,  with  or  against  the  watch,  and  moving  up  and  down 
in  the  mesial  plane  in  seesaw  fashion  every  time  he 
breathed.  With  closed  eyes  turned  to  the  right,  he  felt 
his  head  on  a  level  with  his  feet,  and  also  felt  himself  turn- 
ing in  the  coronal  plane  against  the  watch,  with  or  with- 
out a  slight  sense  of  rotation  about  the  long  axis  from  left 
to  right.  After  the  irrigation  it  seemed  to  the  subject  as 
if  only  the  right  side  of  his  body  was  in  contact  with  the 
couch,  which  is  the  equivalent  of  a  tendency  of  the  body 
to  rotate  from  left  to  right  upon  the  long  axis. 

Here,  again,  is  seen  the  influence  of  turning  the  eyes  in 
certain  directions  upon  the  subjective  interpretation  of 
disturbances  in  equilibrium.  Especially  noteworthy  is 
the  fact  that  turning  the  open  (and  closed)  eyes  to  the 
right  permitted  the  rotary  nystagmus  against  the  watch  to 
overshadow  the  horizontal  element  toward  the  right,  thus 
causing  external  objects  to  appear  to  travel  in  a  circle  in 
the  coronal  plane  when  the  eyes  are  open,  and  giving  the 
subject  a  sense  of  rotation  of  his  body  in  the  same  direc- 
tion when  the  eyes  are  closed.  The  phenomena  are  readily 
explained  upon  principles  laid  down  in  another  cha23ter 
based  partly  on  the  arrangement  and  insertion  of  the  ocu- 


242  SEMICIRCULAR  CANALS 

lar  muscles.  On  opening  the  eyes  during  irrigations  at  70^ 
and  71°  F.  in  the  left  ear,  the  following  conditions  were  ob- 
served: With  the  eyes  directed  straight  ahead,  there  was 
horizontal  nystagmus  with  a  rotary  element  toward  the 
right  and  against  the  watch  respectively ;  with  the  eyes 
turned  to  the  left  the  horizontal  nystagmus  was  at  a  mini- 
mum, and  the  rotary  jerks  seemed  to  be  with  the  watch, 
or  at  least  the  jerks  against  the  watch  were  considerably 
slowed  down ;  with  the  eyes  turned  to  the  right,  there  was 
horizontal  nystagmus  to  the  right,  with  marked  rotary  nys- 
tagmus against  the  watch.  At  times  the  latter  over- 
shadowed the  former. 

In  irrigations  of  the  left  ear  at  118°  F.  for  5  minutes, 
with  the  subject  lying  supine,  the  following  observations 
were  made :  With  eyes  closed  and  directed  straight  ahead, 
the  subject  felt  his  body  revolving  in  the  coronal  plane 
with  or  against  the  watch,  together  with  a  sense  of  seesaw 
movement  up  and  down  from  side  to  side  about  the  long 
axis.  With  eyes  closed  and  turned  strongly  to  the  left, 
the  subject  felt  his  body  rotating  in  the  coronal  plane  with 
the  watch,  together  with  a  sense  of  rotation  about  the  long 
axis  from  right  to  left.  With  eyes  closed  and  turned  to 
the  right,  he  felt  himself  rotating  in  the  coronal  plane 
against  the  watch,  but  without  any  sense  of  motion  about 
the  long  axis. 

Irrigations  were  practised  to  show  that  the  temperature 
of  the  fluid  is  the  important  factor  in  causing  nystagmus 
and  disturbances  of  equilibrium  and  not  the  force  under 
which  the  fluid  entered  the  auditory  canal.  Thus  irriga- 
tions at  65°  F.  with  the  irrigating  receptacle  just  suffi- 
ciently above  the  ear  to  insure  a  flow,  gave  the  character- 
istic nystagmus,  inclination  of  the  head,  etc.  An  irriga- 
tion at  66°  F.  was  then  given  with  the  receptacle  at  18 
inches  above  the  auditory  canal.  The  results  were  the  same 
as  in  the  preceding,  but  perhaps  a  little  accentuated. 
Irrigations  at  101°  F.  were  given  with  the  receptacle  just 
above  the  level  of  the  ear  and  at  a  height  of  4f  feet  above  it. 
In  neither  instance  was  there  nystagmus,  displacement  of 
the  head,  vertigo,  or  disturbance  of  equilibrium.  With 
the  fluid  under  a  pressure  of  4^  feet,  the  blood-pressure 
was  raised  noticeably,  and  tlio  vessels  along  the  handle  of 
the  malleus  immediately  after  the  irrigations  were  much 


PHYSIOLOGY  24B 

contracted,  just  as  in  hot  and  cold  irrigations.  From  these 
experiments  it  is  evident  that  the  temperature  of  the  irri- 
gating fluid  is  the  chief  active  factor  in  causing  labyrin- 
thine reactions  in  aural  irrigations,  the  immediate  rise  in 
blood-pressure  when  the  fluid  enters  the  canal  under  press- 
ure being  an  effect  common  to  powerful  sensory  stimuli 
applied  anywhere  at  the  periphery.  It  is  also  evident 
that  changes  in  the  circulation  are  merely  concomitants 
and  not  the  cause  of  the  labyrinthine  phenomena. 

Cool  irrigations  were  given  in  the  left  ear,  to  determine 
a  point  well  below  the  neutral  temperature,  at  which  even 
a  prolonged  irrigation  had  no  effect  in  causing  nystagmus, 
etc.  Then  the  right  ear  was  experimented  with,  to  deter- 
mine a  point  above  the  neutral  point,  at  which  prolonged 
irrigation  did  not  cause  nystagmus,  etc.  Thus  safe  limits 
were  established  for  the  left  and  right  ears  at  89°  F.  and 
107°  F.  respectively.  Irrigation  of  each  ear  separately 
with  water  at  89°  F.  and  at  107°  F.  for  3  minutes  caused 
no  nystagmus  or  disturbance  of  equilibrium.  A  bilateral 
irrigation  was  now  given  with  water  at  89°  F.  for  the  left, 
and  at  107°  F.  for  the  right  ear,  all  other  conditions  and 
circumstances  being  the  same  as  in  the  preliminary  uni- 
lateral irrigations.  Soon  after  the  commencement  of  the 
irrigation  there  was  mixed  nystagmus  directed  to  the  right 
and  against  the  watch,  with  external  objects  appearing  to 
move  rapidly  to  the  right  and  downward.  The  head  was 
displaced  laterally  to  the  left  and  the  subject  felt  dizzy, 
nauseated  and  exhausted.  These  irrigations  vvere  repeated 
a  number  of  times  with  similar  results. 

From  these  experiments  it  is  clear  that  the  labyrinthine 
disturbances  depend  for  their  causation  rather  upon  the 
relative  differences  in  temperature  of  the  fluid  used  on 
either  side  than  upon  any  absolute  degree  of  heat  or  cold. 
This  shows  conclusively  that  a  constant  labyrinthine  tonus 
is  in  operation  controlling  the  muscular  movements  of  the 
head  and  eyes,  and  also  perhaps  of  much  more  extensive 
parts  of  the  body.  And  since  bilateral  hot  and  cold  irri- 
gations do  not  cause  horizontal  nystagmus  or  lateral  dis- 
placement of  the  head,  it  is  evident  that  in  aural  irriga- 
tions the  cause  of  the  nystagmus  and  of  the  disorders  of 
equilibrium  is  a  disturbance  of  the  normal  irritability  of 
the  peripheral  nerve  endings    (receptors),   whereby  the 


244'  SEMICIRCULAR  CANALS      • 

evenly  adjusted  balanced  mechanisms  that  mediate  laby- 
rinthine tonus  are  temporarily  deranged  and  normal  im- 
pulses evoked  by  acts  of  equilibration  or  locomotion  in 
one  labyrinth  or  the  other  have  an  abnormal  effect,  de- 
pending upon  the  condition  of  the  labyrinthine  receptors 
in  which  they  originate,  i.e.,  whether  the  irritability  of 
the  receptors  of  one  side  is  relatively  increased  or  dimin- 
ished as  compared  with  existing  conditions  in  the  recep- 
tors of  opposite  labyrinth. 

The  vertical  nystagmus  and  the  displacement  of  the 
head  forward  and  backward  that  occur  in  bilateral  cold  or 
hot  irrigations  rather  support  than  contravene  this  view 
since,  as  shall  be  shown  later,  they  depend  upon  depres- 
sion or  exaltation  of  the  receptors  of  one  limb  (viz., 
those  of  the  ampullae  of  both  superior  semicircular  canals) 
of  the  balanced  mechanism  controlling  movements  in  the 
mesial  plane,  thereby  relatively  enhancing  or  depressing 
the  irritability  of  the  receptors  of  the  opposed  limb,  viz., 
those  of  the  ampullae  of  both  posterior  semicircular  canals. 

In  other  words,  bilateral  cold  irrigations  tend  to  depress 
the  sensory  terminals,  i.e.,  to  heighten  the  threshold 
value  in  the  receptors  of  the  ampullae  of  the  superior 
canals,  thereby  lowering  relatively  the  threshold  value  in 
the  receptors  of  their  functional  opponents,  viz. ,  the  pos- 
terior canals.  Similarly  bilateral  hot  irrigations  tend  to 
lower  the  threshold  value  in  the  receptors  of  the  superior 
canals,  thereby  relatively  raising  that  of  the  receptors  in 
the  posterior  canals. 

Besides  the  disorders  already  mentioned  as  following 
aural  irrigations,  disturbances  of  co-ordination  were  also 
observed  at  times.  For  movements  not  particularly  in- 
volved in  acts  of  equilibration,  such  as  touching  the  tip  of 
the  finger  to  the  nose,  the  co-ordination  was  perfect,  pro- 
viding the  subject  had  a  good  basis  of  support,  such  as 
sitting  on  a  chair,  so  that  the  body  as  a  whole  could  be 
easily  steadied  without  any  great  effort  and  thus  supply  a 
reliable  fulcrum  for  the  arm  movements.  At  times  in 
walking,  the  subjects'  "footing  was  not  sure, '^  and  the  co- 
ordination for  gross  hand  movements  was  impaired.  The 
subject  on  walking  after  irrigations,  frequently  complained 
of  a  "sleepy  feeling"  in  the  legs,  and  a  weakness  about 
the  knees.     Occasionally  in  walking  he  erred  in  calcula- 


PHYSIOLOGY  245 

ting  the  distance  of  his  heel  from  the  floor.  How  much 
of  these  symptoms  was  due  to  the  nystagmus  and  general 
weakness  it  would  be  difficult  to  state,  but  it  is  certain 
that  in  general  the  co-ordination  of  the  hands  and  feet, 
even  in  walking,  was  slightly,  if  at  all,  impaired.  The 
position  of  the  feet  and  hands  in  space  was  well  recognized, 
the  chief  trouble  being  to  keep  the  head  perpendicular  and 
so  to  preserv^e  rectilinear  locomotion,  for  the  deviations  in 
walking  seemed  to  be  due  in  most,  if  not  all  cases,  to  the 
deviation  or  displacement  of  the  head  and  upper  part  of 
the  body. 

The  knee-jerks  showed  no  constant  marked  deviations 
from  the  normal.  Occasionally  there  was  slightly  in- 
creased activity  upon  the  side  toward  which  lateral  devi- 
ation of  the  head  occurred.  Sensation  was  unaffected,  ex- 
cept for  the  parsesthesise  already  mentioned,  and  an  extreme 
hypersesthesia  that  frequently  developed  in  the  external 
auditory  canal,  noted  especially  in  hot  irrigations.  So 
great  was  this  at  times,  that  the  slightest  touch  of  the  irri- 
gating nozzle  was  excruciatingly  painful.  In  some  sub- 
jects in  whom  the  membrana  t^Tupani  was  intact,  cold 
irrigations  also,  after  a  few  minutes,  caused  such  intense 
pain  referred  to  the  middle  ear,  that  the  irrigations  had 
to  be  suspended. 

The  par8esthesij3e  of  the  scalp  and  side  of  the  neck  and 
body  that  occur  with  irrigations  have  been  already  alluded 
to.  They  are  described  by  the  subject  as  a  feeling  of  numb- 
ness or  emptiness  in  one  side  of  the  head  and  neck,  usually 
upon  the  side  opposite  to  that  toward  which  the  lateral 
deviation  of  the  head  occurs.  This  is  frequently  cou2:)led 
with  a  sense  of  "drawing"  of  the  muscles  (voluntary  com- 
pensation) upon  that  side  and  a  sense  of  dead  weight  or 
heaviness  upon  the  side  toward  which  lateral  deviation  of 
the  head  takes  place. 

Partesthesise,  referred  to  the  homolateral  half  of  the 
head,  also  occur  when  the  external  auditory  canal  is 
plugged,  so  that  free  access  of  air  and  liquids  to  the  tym- 
panic membrane  and  the  adjacent  area  of  the  external 
auditory  canal  is  prevented.  This  was  done  in  order  to  de- 
termine whether  cold  irrigations  of  the  external  auditory 
canal  without  coming  in  contact  with  the  driun  membrane, 
and  a  small  portion  of  the  canal  immediately  contiguous  to 


24G  SEfflCIRCULAR  CANALS 

it,  would  cause  nystagmus  or  disturbance  of  equilibrium. 
Under  these  circumstances  irrigations  in  the  left  ear  at  74° 
F.  for  4  minutes  were  without  effect.  The  only  result  was  a 
peculiar  emptiness  or  lightness  all  over  the  left  side  of  the 
head  accompanied  by  autophony.  The  feeling  is  well 
known  to  those  who  have  had  inflammatory  exudations  in 
the  t}mipanum.  It  seems  to  be  due  to  the  relatively  in- 
creased bone  conduction  whereby,  on  account  of  the  dimin- 
ished air  conduction,  impressions,  ordinarily  not  heard, 
reaching  the  peripheral  auditory  apparatus  on  that  side 
by  way  of  the  cranial  bones  become  relatively  exaggerated 
by  exclusion  of  the  tympanum  as  a  means  of  communica- 
tion of  sound  vibrations  in  the  usual  way. 

Similarly  the  ear  canals  w^ere  plugged  to  study  the 
effects  upon  equilibrium  when  the  subject  dived  under 
water.  There  was  no  noticeable  disturbance  observed,  but 
w^hen  only  one  ear  canal  was  plugged,  a  sense  of  emptiness 
or  lightness  upon  that  side  was  experienced.  This  was 
accompanied  by  autophony.  This  seems  to  indicate  that 
the  cochlear  receptors  also  mediate  some  kind  of  tonus, 
and  that  these  receptors  on  either  side  of  the  body  stand 
to  each  other  in  the  relation  of  balanced  mechanisms. 

It  was  noticed  on  several  occasions  that  in  persons  well 
beyond  middle  life  and  in  those  suffering  from  general 
arterio-sclerosis  as  well  as  those  suffering  from  "nerve 
deafness, ' '  irrigations  are  not  so  potent  in  producing  the 
characteristic  disturbances  as  similar  irrigations  practised 
on  younger  individuals.  In  a  case  of  locomotor  ataxia, 
in  the  beginning  of  the  ataxic  stage,  the  sensitiveness  of 
the  labyrinthine  mechanisms  was  distinctly  increased. 

In  a  person  subject  to  gastric  crises  of  tabetic  origin, 
but  in  whom  the  stage  of  ataxia  had  not  yet  set  in,  hot 
and  cold  irrigations  had  but  little  effect.  All  forms  of 
deafness  seemed  to  be  temporarily  improved,  especially  by 
hot  irrigations  graded  carefully  to  reach  the  point  of  effi- 
ciency. Little  permanent  good  perhaps  is  to  be  expected 
in  professional  and  senile  deafness.  Here  the  cause  is  due 
primarily  to  disease  of  the  cochlear  nerve  as  shown  by 
Haberman  and  Alexander.^"**  Nevertheless,  since  circula- 
tory changes  and  disease  of  the  blood-vessels  are  seldom 
wanting,  and  especially  since  absence  of  collateral  anasto- 
moses is  one  of  the  chief  factors  causing  the  ' '  elective  vul- 


PHYSIOLOGY  247 

nerability"  of  the  cochlear  nerve,  it  seems  that  anything 
which  offers  hope  of  even  temporarily  improving  the  cir- 
culation in  the  internal  ear,  without  adding,  as  many 
drugs  undoubtedly  do,  to  the  danger  of  nerve  degeneration, 
should  be  welcomed. 

During  and  after  aural  irrigation  of  a  degree  sufficient 
to  disturb  the  equilibrium,  it  was  observed  that,  to  resisted 
movement,  the  subject  was  much  stronger  on  the  side  to- 
ward which  the  head  inclined.  Thus  with  cold  irrigations 
of  the  left  ear,  slight  force  on  the  right  side  of  the  head 
was  sufficient  to  disj^lace  it  toward  the  left,  vrhilst  it  took 
much  greater  force  applied  on  the  left  side  to  dis|)lace  the 
head  toward  the  right.  In  the  latter  instance,  the  subject's 
muscles  acted  strongly  and  together,  whilst  in  the  former 
there  seemed  to  be  a  want  of  combined  action  as  manifested 
by  inefficiency  and  jerky  irregularities  in  the  muscular 
contractions.  Cold  irrigations  seem  therefore  to  displace 
the  head  laterally  by  an  impairment  of  function  of  the 
muscles  of  the  opposite  side  of  the  body,  which  tend  to 
hold  the  head  in  the  erect  j^osition.  Hot  irrigations  seem, 
on  the  other  hand,  to  act  by  enhancing  the  muscular  func- 
tion upon  the  contralateral  side. 

The  conclusions  are: 

1.  That  the  phenomena  of  aural  irrigations  are,  in  all 
■essential  respects,  analogous  to  those  caused  by  rotations. 
Thus :  (a)  Irrigation  of  the  left  ear  with  cold  water  is 
equivalent  to  the  primaiy  effects  of  rotation  about  the  long 
axis  from  left  to  right,  (b)  Irrigation  of  the  left  ear  with 
hot  water  is  equivalent  to  the  primary  effects  of  rotation 
about  the  long  axis  from  right  to  left,  (c)  Bilateral  irri- 
gation with  cold  water  is  equivalent  to  the  primary  effects 
of  rotation  in  the  mesial  plane  "occiput  first"  (relative 
stimulation  of  the  ampullary  receptors  of  the  posterior 
canals) .  (d)  Bilateral  irrigation  with  hot  water  is  equiva- 
lent to  the  primary  effects  of  rotation  in  the  mesial  plane 
"face  first"  (absolute  stimulation  of  the  ampullar}^  recep- 
tors of  the  superior  canals) . 

2.  That  reactionary  secondary  phenomena  may  occur 
after  aural  irrigations  as  after  rotations,  but  that  with  the 
former  their  appearance  is  slower  and  much  less  manifest 
than  with  the  latter. 

3.  That  in  aural  irrigations,  as  in  rotations,  there  are 


248  SEMICIRCULAR   CANALS 

various  forms  of  subsidiary  or  latent  nystagmus  present, 
simultaneously  with  the  type  or  combination  which  is 
dominant  and  characteristic  for  certain  irrigations,  and 
for  rotations  in  a  certain  plane  and  direction;  that  by 
turning  the  closed  eyes  in  certain  directions,  the  dominant 
combination  may  be  inhibited,  thereby  allowing  one  of 
the  other  forms  of  nystagmus  to  impress  the  subject,  and 
so  beget  the  subjective  sense  of  motion  usually  associated 
with  that  particular  type  of  nystagmus. 

8.  That  the  temperature  of  the  irrigating  fluid  is  the 
important  factor  in  causing  the  labyrinthine  phenomena 
in  aural  irrigations. 

4.  That  in  the  lateral  deviations  of  the  head,  cold  irri- 
gations act  by  depressing  the  function  of  the  muscles  on 
the  opposite  side  of  the  neck  and  head,  whilst  hot  irriga- 
tions act  by  enhancing  the  muscular  efficiency  or  tonus  on 
the  contralateral  side. 

5.  That  each  labyrinth  exerts  reflexly  a  nicely  adjusted 
tonus  on  the  related  muscles  that  control  the  equilibrium 
of  the  head  and  upper  part  of  the  body;  that  aural  irriga- 
tions act  by  alteration  of  the  normal  irritability  of  the 
labyrinthine  receptors  on  one  side  or  the  other,  whereby 
the  evenly  adjusted  mechanisms  of  labyrinthine  tonus  on 
either  side  of  the  body  are  deranged,  and  afferent  im- 
pulses, evoked  by  ordinary  acts  of  equilibration  or  loco- 
motion have  an  abnormal  value,  enhanced  or  the  opposite; 
that  as  a  consequence,  abnormal  responses  on  the  part  of 
the  related  muscles  result,  depending  upon  the  relative 
condition  of  irritability  that  obtains  in  the  labyrinthine 
receptors  as  compared  with  the  condition  of  irritability 
of  the  corresponding  receptors  in  the  opposite  labyrinth. 

6.  That  the  disturbances  of  co-ordination  that  accom- 
pany aural  irrigations  affect  mainly  movements  of  the 
body  calculated  to  steady  the  upper  portion  of  the  body 
upon  a  lower  fixed  portion,  and  that  consequently  there  is 
no  true  inco-ordi nation  of  the  feet  or  hands. 

7.  That  sensory  stimulation  of  the  external  auditory 
canal  is  not  the  cause  of  the  characteristic  phenomena  of 
aural  irrigations. 

8.  That  hot  and  cold  irrigations  act  by  increasing  and 
depressing  respectively  the  irritability  of  the  labyrinthine 
receptors  j  that  these  effects  are  brought  about  by  direct 


PHYSIOLOGY  249 

conduction  through  the  osseous  structure  situated  just 
above  the  attachment  of  the  membrana  tympani  where  lie, 
in  close  proximity  to  the  surface,  the  horizontal  semicircu- 
lar canal  with  its  ampulla  and  the  ampulla  of  the  superior 
semicircular  canal,  the  macula  of  the  utricle  being  in 
close  proximity. 

9.  That  aural  irrigations  are  accompanied  by  paraes- 
thesiae  of  the  neck  and  scalp  which  are  fairly  characteris- 
tic and  constant  in  their  relations  to  the  labyrinth  affected, 
and  which  indicate  probably  impaired  cerebellar  function. 

10.  That  aural  irrigations  are  a  possible  aid  in  the 
treatment  of  "nerve"  and  other  forms  of  deafness  where 
little  is  to  be  expected  from  the  ordinary  methods;  and 
that  they  may  possibly  help  in  arresting  the  progress  of 
degeneration  by  enhancing  the  local  circulation. 


CHAPTER  XVII 

THE   EFFECTS   OF  AURAL   IRRIGATIONS   UPON   THE 

EYES 

The  effect  of  aural  irrigations  upon  the  pupils  was 
studied.  The  results,  however,  whilst  usually  striking 
were  by  no  means  uniform.  The  sequence  of  the 
phenomena  in  cold  irrigations  (62°-75°  F.)  most  fre- 
quently appeared  to  be  as  follows :  The  first  effect  imme- 
diately following  impact  of  the  fluid  against  the  interior 
of  the  external  auditory  canal  was  dilatation.  This  was 
soon  followed  by  constriction,  first  upon  the  side  of  irri- 
gation and  later  upon  the  opposite  side.  After  a  period 
of  from  five  to  fifteen  seconds  both  pupils  again  became 
dilated.  From  this  point  on,  there  was  usually  a  condi- 
tion of  alternating  dilatation  and  constriction  (hippus), 
the  average  size  of  the  pupils  being  that  of  moderate  con- 
striction. The  hippus  was  studied  under  a  strong  light 
from  the  ophthalmoscope  and  in  moderate  daylight.  In 
cold  irrigations  there  was  a  tendency  of  the  pupil  upon 
the  side  of  irrigation  to  constriction  as  compared  with  its 
fellow,  though  in  some  instances  it  was  the  larger  of  the 
two.  During  the  irrigations  there  was  congestion  of  the 
conjunctiva  of  both  eyes,  but  more  marked  upon  the  side 
of  irrigation. 

Immediately  following  cold  irrigations,  the  pupils  in 
many  instances  became  constricted  on  closing  the  eyes, 
but  one  minute  after  the  irrigation  the  pupils  did  not  con- 
tract but  rather  dilated  somewhat  on  closing  the  eyes. 
The  constriction  of  the  pupils  on  closing  the  eyes  accords 
with  a  general  tendency  to  sleep  during  the  irrigations 
when  the  eyes  were  kept  open  only  with  an  effort. 

In  hot  irrigations  (115°-119°  F.)  the  pupillary  phe- 
nomena were  similar  to  those  in  cold  irrigations,  but  there 
seemed  to  be  a  tendency  to  relative  constriction  in  the 
pupil  on  the  contralateral  side. 

250 


PHYSIOLOGY  251 

In  a  bilateral  irrigation  at  T9°  F.  in  the  left,  and  107° 
F.  in  the  right  ear,  the  left  pupil  was  larger  than  the  right. 
Closing  the  eyes  seemed  at  times  to  revive  the  waning 
symptoms  of  disturbances,  whilst  at  other  times  it  tended 
to  relieve  them. 

The  above  conclusions  were  based  upon  numerous 
observations  made  in  the  general  study  of  irrigations. 
Later,  a  series  of  irrigations  was  undertaken  with  a  view 
to  a  more  specialized  attempt  in  the  study  of  the  pupillary 
reactions.  Irrigations  were  practised  with  the  subject 
lying  supine,  and  in  such  a  position,  that  a  moderate  uni- 
form daylight  illuminated  both  eyes.  In  some  of  the  ir- 
rigations, by  carefully  plugging  the  inner  third  of  the 
external  auditory  canal  with  non-absorbent  cotton,  care  be- 
ing taken  to  avoid  contact  with  the  membrana  tjmipani, 
an  attempt  was  made  to  differentiate  the  effects  of  thermic 
stimulation  of  the  sensory  ner\^es  of  the  canal  from  those 
due  to  labyrinthine  stimulation.  The  pupils  were  ob- 
served, and  rough  drawings  made  from  them  before,  at  the 
onset  of,  during,  and  after  each  irrigation.  The  hippus 
was  also  studied,  and  an  attempt  made  to  measure  the 
duration  and  extent  of  the  alternating  variations.  The 
pulse-rate  and  blood-pressure  were  also  observed  during 
some  of  the  irrigations.  In  some  instances  during  the 
irrigations  the  pupil  reactions  in  accommodation  were  also 
studied. 

As  the  mechanisms  of  pupillary  dilatation  and  con- 
striction are  somewhat  complex,  and  as  there  is  by  no 
means  a  general  uniformity  of  opinion  as  to  their  modus 
operandi,  the  observations  made  in  this  last  series  of  irri- 
gations are  set  forth  somewhat  in  detail. 

Irrigation  at  117°  F.,  with  the  ear  partially  stuffed — • 
Pupils  before  irrigation  were  moderately  dilated  the 
left  being  somewhat  larger  than  the  right.  At  onset  of 
irrigation  the  pupils  were  somewhat  contracted,  with 
the  left  a  little  smaller  than  the  right.  Later  on  the 
pupils  grew  still  smaller  and  remained  small  and  of 
equal  size.  During  the  progress  of  the  irrigation  there 
was  hippus  of  very  short  range,  and  occurring  at  intervals 
of  from  1  to  3  seconds.  The  pupils  were  smaller  if 
anything,  and  equal,  and  did  not  dilate  much  in  fixation 
for  distance.     One  minute  after  irrigation  the  pupils  were 


252  SEMICIRCULAR   CANALS 

dilated  almost  to  the  degree  observed  before  irrigation  and 
now  they  were  equal.  The  subject  felt  numb  and  cold  in 
the  left  side  of  the  head. 

Irrigation  at  117°  F.  with  no  stuffing  in  the  ear.  Before 
irrigation  the  pupils  were  moderately  large,  the  left 
being  slightly  the  larger.  At  the  onset  of  irrigation  the 
pupils  showed  no  change  for  half  a  minute.  During 
the  irrigation  the  pupils  were  somewhat  contracted 
the  left  being  still  a  little  the  larger.  The  hippus  cycle 
extended  over  a  period  of  4  seconds.  Four-fifths  of  the 
time  was  taken  up  with  the  phase  of  contraction  of  the 
pupil  and  the  resting  stage  before  the  next  dilatation, 
whilst  one-fifth  of  the  time  was  consumed  in  the  actual 
process  of  dilatation.  The  dilatation,  therefore,  was  more 
active  than  the  constriction,  and  its  extent  was  about  one- 
fourth  of  the  width  of  the  iris.  At  this  stage  the  pupils 
were  still  smaller  and  equal.  During  fixation  for 
distance,  the  pupils  dilated  somewhat  and  the  range  of 
the  hippus  was  diminished.  After  irrigation  the  pupils 
began  to  widen,  and  the  hippus  ceased.  Three  minutes 
after  irrigation  the  pupils  were  equal  and  about  as  large 
as  they  were  before  irrigation. 

Irrigation  at  75°  F.  without  stuffing  in  the  ear.  Before 
irrigation  the  pupils  were  moderately  large  and  equal. 
At  onset  of  irrigation  the  pupils  showed  no  change. 
During  irrigation  the  pupils  were  slightly  constricted, 
the  left  more  so  than  the  right.  Intermittent  nystagmic 
movements ;  no  hippus  present.  Pupils  contracted  in  ac- 
commodation for  near  vision;  the  subject  was  drowsy; 
the  eyelids  were  constantly  closing. 

Irrigation  at  65°  F.  with  ear  plugged.  Before  irriga- 
tion the  pupils  were  moderately  large,  the  left  being  the 
larger.  At  this  time  there  was  hippus  of  wide  range.  In 
the  stage  of  constriction,  the  pupils  still  further  contracted 
in  fixation  for  near  vision  (accommodation)  and  dilated 
in  fixation  ior  distance,  but  only  to  an  extent  correspond- 
ing with  that  to  whicli  they  had  previously  contracted 
for  near  vision.  In  other  words,  in  fixation  for  distance, 
the  pupil  could  n(jt  relax  the  constrictor  effect  to  any  ex- 
tent, whilst  in  fixation  for  near  vision,  the  pupil  could 
contract  still  further.  Fixation  for  distance  seems  to 
make  the  subject  drowsy.  The  pulse-rate  was  72  and  the 


PHYSIOLOGY  253 

blood-pressure  105.  At  the  onset  of  the  irrigation,  the 
pupils  showed  no  appreciable  change  in  size,  though  the 
blood-pressure  rose  to  115  with  a  pulse-rate  of  76.  During 
the  irrigation  the  pupils  showed  little,  if  any,  change  in 
size.     Hippus  of  short  range  was  present. 

Irrigation  at  65°  F.  without  plugging  the  ear.  Before 
irrigation,  the  pupils  were  moderately  large,  the  left 
being  slightly  the  larger.  There  was  some  hippus  present. 
The  blood-pressure  was  115  and  the  pulse-rate  80.  At  the 
onset  of  the  irrigation,  the  pupils  were  constricted 
somewhat,  the  left  more  so  than  the  right.  Hippus  of  short 
range  was  present.  The  blood-pressure  was  125,  and  the 
pulse-rate  80.  During  irrigation  the  pupils  became  still 
more  constricted,  the  left  being  still  the  smaller.  Hip- 
pus of  short  range  was  present.  There  was  conjunctival 
congestion  more  marked  in  the  left  eye. 

Irrigation  at  119°  F.  with  the  ear  stuffed.  Before 
irrigation,  the  pupils  were  moderately  large,  the  left 
being  the  larger.  Each  pupil  contracted  to  light,  but  the 
left  showed  at  times  a  tendency  not  to  contract.  The 
blood-pressure  was  105  and  the  pulse-rate  76.  At  the  on- 
set of  irrigation  the  pupils  showed  no  change.  Both  con- 
tracted for  near  vision.  During  irrigation  the  pupils 
became  somewhat  constricted,  the  left  being  still  the 
larger.  One  minute  after  irrigation,  the  pupils  were 
about  as  they  were  before  the  irrigation. 

Irrigation  at  119°  F.  without  plugging  the  ear.  Before 
irrigation,  the  pupils  were  small  and  equal.  Hippus  was 
present  and  was  of  a  twofold  variety.  Excursions  of  long 
range  occurred  every  5  to  10  seconds,  the  dilatation  being 
executed  in  three  or  four  bounds  with  the  constricting 
phase  setting  in  immediately  on  the  completion  of  dilata- 
tion. Between  these  larger  excursions,  i.e.,  in  the  resting 
stage  at  the  end  of  constriction,  excursions  of  short  range 
occurred  each  dilatation  giving  place  to  a  constriction  of 
equal  range.  Noise  made  by  clapping  the  hands  near  the 
ear,  caused  the  pupil  to  dilate  to  a  slight  extent.  Just 
before  the  onset  of  the  irrigation,  the  pupils  were  moder- 
ately small  and  equal.  At  the  onset  of  the  irrigation,  the 
eyelids  blinked,  and  the  pupils  dilated  somewhat,  being 
equal  size.  A  moment  later,  the  pupils  were  unchanged, 
except  that  the  left  was  larger  than  the  right.     Hippua 


254  SEMICIRCULAR   CANALS 

was  present,  but  not  as  frequent  or  active  as  before  irri- 
gation. During  irrigation,  the  pupils  became  small  and 
equal,  in  spite  of  the  fact  that  the  subject  had  a  sharp 
pain  in  the  ear  all  through  the  irrigation.  One  minute 
after  irrigation,  the  pupils  were  about  the  same  as  before 
irrigation. 

Irrigation  at  62°  F,  without  plugging  the  ear.  Before 
irrigation,  the  pupils  were  moderately  large  and  equal, 
but  changed  and  became  small  and  equal  just  before  the 
onset  of  the  irrigation.  At  the  onset  of  the  irrigation, 
the  pupils  were  moderately  constricted  and  equal.  There 
was  little,  if  any,  hippus  before  the  onset  of  nystagmus. 
Closing  the  eyes  caused  dilatation  of  the  pupil;  opening 
them  caused  a  sharp  constriction.  Toward  the  end  of 
the  irrigation,  the  pupils  were  moderately  small,  with  the 
left  somewhat  the  larger.  Just  after  irrigation,  the  pupils 
were  unchanged,  but  shading  the  eyes  at  this  time  caused 
a  dilatation  that  was  brisker  than  during  the  irrigation, 
and  the  constriction  to  light  seemed  to  be  less  sharp.  The 
subject  felt  no  pain  during  this  irrigation.  After  the  irri- 
gation he  felt  heavy  and  yawned  much.  Finally  he  fell 
asleep. 

From  the  foregoing  it  appears  that  the  immediate  effect 
of  both  hot  and  cold  irrigations,  with  and  without  plug- 
ging of  the  ear,  was  either  nil  or  resulted  in  constriction 
of  the  pupils.  It  should  be  noted  that,  as  a  rule,  the  con- 
dition of  the  XDupils  before  irrigation  was  that  of  dilata- 
tion. Where  the  pupils  Avere  small,  one  hot  irrigation 
without  plugging  caused  a  slight  dilatation,  but  not  quite 
up  to  the  degree  that  usually  prevailed  before  the  irriga- 
tions. Partial  plugging  of  tlie  ear,  so  as  to  keep  the  irri- 
gating fluid  from  entering  the  inner  third  of  the  auditoiy 
canal,  seemed  to  have  no  particular  effect  upon  the  im- 
mediate results  of  the  irrigations.  It  had  some  effect, 
however,  upon  the  results  of  prolonged  irrigation.  Thus 
in  hot  irrigations,  with  the  ear  stuffed,  tlie  pupils  did  not 
contract  so  much  as  in  hot  irrigations  without  stuffing; 
and  hippus  was  absent  or  of  slight  range  in  the  former 
case,  whilst  in  the  latter,  it  was  generally  present  and  oc- 
casionally of  wide  range.  In  one  cold  irrigation,  with 
the  ear  plugged,  the  pupils  did  not  contractor  become  un- 
equal, whilst  in  several  cold  irrigations  without  plugging, 


PHYSIOLOGY  255 

the  pupils  almost  invariably  contracted  somewhat  and  be- 
came unequal,  that  on  the  side  of  irrigation  being  the 
smaller.  In  cold  irrigations  the  hippus  seemed  to  be 
about  the  same ;  that  is,  slight  and  of  short  range  with  and 
without  plugging  of  the  ear.  The  inequality  of  the  pupils 
seems  therefore  to  belong  to  the  phenomena  of  labyrin- 
thine disturbance,  and  judging  from  the  effect  of  cold  irri- 
gations in  causing  the  pupil  on  the  side  of  irrigation  to 
become  constricted  it  seems  probable  that  the  inequality 
of  the  pupils,  seen  at  times  in  hot  irrigations,  is  due  to  a 
relative  constriction  of  the  contralateral  pupil.  The 
changes  in  the  blood-pressure  and  pulse-rate  that  occurred 
during  the  irrigations  did  not  seem  to  bear  any  definite 
relation  to  the  changes  in  the  pupil.  In  one  instance 
hippus  of  long  range  was  present  before  irrigation.  Here, 
however,  it  should  be  noted  that  the  subject  had  already 
had  seven  irrigations.  The  hippus,  therefore,  in  this  in- 
stance may  have  been  the  result  of  previous  irrigations. 
Judging  from  the  time  of  its  appearance  and  from  its 
occurrence  with  and  without  plugging  of  the  ear  canal,  it 
seems  that  the  ordinary  alternating  movements  of  the  pupil 
can  hardly  be  attributed  to  the  effect  of  the  irrigations 
upon  the  labyrinthine  receptors.  However,  it  seems  prob- 
able that  where  the  range  of  excursion  was  extensive,  the 
hippus  was  due  to  more  than  stimulation  of  the  receptors 
in  the  auditory  canal  and  must  probably  be  classed  among 
the  labyrinthine  effects.  This  form,  which  perhaps  alone 
deserves  the  name  of  hippus,  occurred  only  when  the  ear 
canal  was  not  plugged,  and  generally  some  time  after  the 
onset  of  an  irrigation.  In  the  accommodation  tests  it  ap- 
peared that  no  matter  how  small  the  pupils  were,  they 
could  be  made  smaller  by  fixation  for  near  vision,  whilst  in 
fixation  for  distance  the  range  of  dilatation  never  seemed 
to  exceed  the  limits  of  the  primary  state  of  the  pupil, 
i.e.,  before  fixation  for  near  vision  was  tried.  During  a 
cold  irrigation  it  was  seen  that  after  shading  the  eyes  the 
pupils  reacted  quickly  on  readmission  of  light,  whilst 
after  the  irrigation  the  constrictor  reaction  was  less  active. 
We  may  therefore  conclude  that,  in  general,  hot  and 
cold  irrigations  tend  to  cause  unequal  pupillary  constric- 
tion, hippus,  conjunctival  congestion,  a  tendency  of  the 
eyelids  to  close,  and  a  distinct  inclination  to  sleep. 


256  SEMICIBCULAE  CANALS 

The  tendency  of  the  j)upils  to  contract,  even  at  the  onset 
of  cold  or  hot  irrigations,  is  remarkable,  because  it  is  well 
known  and  accepted  that  stimulation  of  any  sensory  nerve, 
as  well  as  of  numerous  areas  of  the  cerebral  cortex,  is  at- 
tended with  pupil  dilatation,  whilst  but  few  areas  of  the 
brain  and  cerebellum  are  associated  directly  or  indirectly 
with  pupil  constriction. 

During  these  tests  the  illumination  was  by  daylight  of 
moderate  dulness.  The  subject  was  cautioned  against  fix- 
ing his  vision  for  near  or  distant  objects.  All  the  irriga- 
tions were  given  in  the  left  ear  with  the  subject  lying  upon 
the  back. 

By  way  of  contrast  the  pupils  were  similarly  studied  in 
rotations  about  the  long  axis.  In  general  it  was  found 
that  immediately  on  abrupt  cessation  of  rotation  from  left 
to  right  the  pupils  first  became  moderately  dilated  and  soon 
after  contracted.  Hippus  was  present  of  large  excursion, 
the  cycle  covering  a  period  of  7  to  8  seconds.  Later  the 
pupils  became  still  smaller  and  the  right  always  being 
the  smaller,  although  at  times  the  left  pupil  also  became 
very  small.  Three  minutes  after  a  rotation,  the  pupils  be- 
came almost  as  large  as  before  rotation,  and  there  was  still 
some  hippus  present. 

Upon  cessation  of  a  rotation  from  right  to  left  the 
pupils  dilated  for  a  short  time  and  later  contracted.  At 
this  point  hippus  appeared  with  cycles  of  a  duration  of 
from  8  to  7  seconds.  On  closing  the  eyes  the  pupils  dilated. 
Six  and  a  half  minutes  after  rotation  the  pupils  were 
somewhat  constricted,  as  compared  with  the  normal  before 
rotation. 

At  times,  during  aural  irrigations  and  following  rota- 
tions, great  difficulty  was  experienced  in  observing  the 
fundus  oculi,  owing  manifestly  to  disturbances  in  the 
mechanisms  of  refraction.  These  changes  are  interesting 
because  changes  in  refraction  have  frequently  been  noted 
in  connection  with  the  study  of  the  physiology  of  the  cer- 
vical sympathetic.  Thus  Morat  and  Doyon  ^^^  found 
diminution  in  size  of  the  anterior  crystalline  lens  images 
after  section,  and  enlargement  of  the  same  images  after 
stimulation  of  the  cervical  sympathetic.  Hess  and 
Heine,  ^'^"^  however,  demonstrated  that  stimulation  of  tlie 
sympathetic  dilates  the  pupil  without  altering  the  condi- 


PHYSIOLOGY  257 

tion  of  the  ciliary  muscle,  and  attributed  the  errors  of  re- 
fraction to  changes  in  the  peripheral  portions  of  the  cornea 
and  lens  by  dilatation  of  the  pupil.  Rohmen  and  Dufour  "^^ 
concluded  that  the  alteration  in  refraction  on  dilatation 
of  the  pupil  was  not  necessarily  due  to  actual  change  in 
the  lens,  and  that  the  sympathetic  cannot  cause  negative 
accommodation.  Terrien  and  Comus"^  showed  that 
stimulation  of  the  cervical  sympathetic,  after  section, 
caused  an  increase  in  refraction  of  the  eye  from  1  to  2.5  D. 
This  change  sets  in  before  dilatation  of  the  pupil  and  is 
of  shorter  duration  than  the  latter.  These  authors  give 
no  satisfactory  explanation  of  the  phenomenon. 

From  these  results  it  is  evident  that  stimulation  of  the 
cervical  sympathetic  in  some  way  changes  the  refraction  of 
the  eye.  It  is  probable  that  the  changes  in  refraction 
caused  by  irrigations  and  rotations  are  similarly  caused, 
but  they  were  observed  when  the  pupil  was  under  the  in- 
fluence of  homatropin  just  after  rotations  and  during 
aural  irrigations. 

In  discussing  hippus  it  must  be  remembered  that  ordi- 
narily when  the  intensity  of  light  entering  the  eye  is 
altered,  the  pupil  contracts  and  oscillates  rapidly,  alter- 
nately overstepping  the  mark  in  contraction  and  in  dila- 
tation, until  finally  it  settles  down  in  contraction  which 
is  slightly  less  than  that  first  exhibited.  In  abnormal 
conditions  this  normal  oscillation  of  the  pupil  may  be  ex- 
aggerated as  follows:  (1)  Where  the  excursions  are  wide, 
readily  seen,  and  independent  of  increased  intensity  of 
light  falling  upon  the  eye.  This  condition  is  known  as 
hippus.  It  is  due  to  rhythmic  activity  of  the  nerve 
centres  and  is  ordinarily  not  a  peripheral  phenomenon. 
(2)  Where  there  is  lack  of  sustained  contraction  under 
the  influence  of  light.  Here  the  pupil  contracts  sluggishly 
when  the  intensity  of  the  light  is  increased  and  whilst  the 
light  is  left  constant  the  pupil  slowly  dilates  and  often 
with  sluggish  oscillations.  This  is  a  pathological  phe- 
nomenon caused  by  diminished  conductivity  in  the  affer- 
ent paths  of  the  light  reflex,  i.e.,  usually  in  the  optic 
nerve,  e.g.,  retorbulbar  neuritis  (Parsons*''^).  With  the 
hippus  occurring  during  aural  irrigations  were  associated 
at  times  the  ordinary  rhythmic  oscillations  of  the  pupil. 
In  the  latter  the  contractions  and  dilatations  were  evenly 


258  SEMICIRCULAR   CANALS 

balanced  and  of  about  equal  range  and  duration.  In  the 
larger  excursions,  without  alteration  of  the  light  condi- 
tions, the  dilatation  was  sudden  and  abruptly  executed, 
whilst  the  contraction  began  immediately  following  the 
sudden  dilatation,  but  was  carried  out  so  slowly  that  it 
was  difficult  to  say  when  it  ended.  After  closely  observ- 
ing this  form  of  hippus  it  is  hard  to  avoid  concluding 
that  in  irrigations,  etc.,  it  results  from  hypertonus  of  the 
pupillo-constrictor  mechanism  which,  from  time  to  time, 
is  momentarily  overcome  by  the  activity  of  the  pupillo- 
dilator  mechanism.  Anderson  ^^^  found  that  hippus  fre- 
quently occurred  after  section  of  the  third  nerve,  and  that 
it  was  excited  by  tactual  stimuli  or  by  a  certain  state  of 
anaesthesia.  On  section  of  the  cervical  sympathetic  the 
hippus  ceased.  These  observations,  however,  are  quite 
compatil^le  with  the  theory  of  reciprocal  innervation  be- 
tween the  dilator  and  constrictor  mechanisms. 

Waymouth  Reed,  "^  because  of  the  electric  phenomena 
manifested  during  contraction  of  the  sphincter  iridis, 
concludes  that  such  a  relation  exists.  Anderson,  113,193 
however,  opposes  this  view,  because:  (1)  after  section  of 
the  third  nerve  variations  in  illumination  do  not  affect 
the  pupil;  (2) paradoxical  pupil  dilatation  may  arise  and 
last  a  minute  in  bright  sunlight  and  (3)  in  the  inequality 
of  the  pupils  following  paralysis  of  one  dilator  mechanism 
the  inequality  is  not  diminished  but  increased  by  bright 
illumination  of  the  eyes.  Inasmuch  as  the  modus  oper- 
andi of  paradoxical  pupil  dilatation  is  not  sufficiently 
understood,  conclusions  based  on  evidence  derived  from 
the  phenomenon  must  be  regarded  with  suspicion.  Then 
again  the  conditions  ol^taining  in  the  pupil  after  section 
of  the  third  nerve  or  of  the  cervical  sympathetic  are  such 
as  tend  to  mask  reactions  from  alterations  in  illumina- 
tion. On  the  other  hand  Jessop  ^^-^  never  saw,  in  the  iris, 
dilator  fibres  to  compare  in  thickness  and  strength  with 
those  of  the  sphincter.  It  is  difficult,  therefore,  to  under- 
stand how  such  a  feeble  dilator  mechanism  can,  for  in- 
stance in  stimulation  of  the  sympathetic,  overcome  the 
stronger  constrictor  muscle  without  the  intervention  of 
some  such  process  as  reciprocal  innervation.  And  as  re- 
ciprocal innervation  is  of  such  widespread  occurrence  and 
plays  such  an  important  role  in  bodily  adjustments  it 


PHYSIOLOGY  259 

may  be  accepted,  pending  further  'researches,  that  it  is 
utilized  in  the  mechanism  of  pupillary  phenomena. 

In  the  hippus  that  occurs  with  aural  irrigations  and 
rotations  the  question  arises :  Is  it  the  result  of  pathic 
stimuli  ?  V.  Bechterew  ^^^  associates  the  light  reflex  with 
the  pathic  or  sensory,  and  showed  that  the  dilatation  in 
the  latter  was  due  to  inhibition  of  the  former.  This 
seems  to  make  the  sensory  dilatation  as  it  were  part  of  a 
nociceptive  reflex.  Anderson  ^^^  agrees  with  v.  Bech- 
terew's  view  but  says  that  there  is  at  the  onset  of  the  re- 
flex a  rapid  short  dilatation  due  to  augmented  dilator  tone. 
Inasmuch  as  the  dilatation  in  aural  irrigations  usually 
commenced  only  after  the  lapse  of  a  period  sufficient  to 
permit  the  irrigations  to  affect  the  labyrinthine  receptors, 
and  inasmuch  as  the  state  of  the  pupils  in  irrigations 
was,  in  general,  that  of  unequal  contraction  rather  than 
of  dilatation,  it  seems  that  the  hippus  is  to  be  considered 
as  an  associated  labyrinthine  phenomenon  caused  probably 
by  subjective  sensations  attending  the  disturbances  of 
equilibrium.  The  positive  element  of  the  dilating  phase 
of  the  hippus  seems  due  to  increased  tonus  in  the  dilator 
mechanism.  Such  increase  of  tonus  always  follows  in- 
hibition and  lowers  the  threshold  value  at  the  commence- 
ment of  the  final  common  path  for  the  paths  inhibited 
(Sherrington^^).  Additional  factors  in  augmenting  the 
dilator  tonus  are  re-enforcement  or  bahnung  and  summa- 
tion of  stimuli,  whether  originating  in  the  cerebral  cortex 
or  at  the  periphery.  The  negative  element  in  dilatation 
is  due  to  inhibition  of  constrictor  tonus,  the  threshold  for 
afferent  constrictor  impulses  being  raised  at  the  commence- 
ment of  the  final  common  path,  just  as  that  for  afferent 
dilator  impulses  becomes  lowered.  In  this  manner  alter- 
nate changes  in  threshold  values  at  the  commencement  of 
the  final  common  paths  give  rise  to  the  rh}i:hmic  dilata- 
tions and  contractions  of  the  pupil  (alternating  reflexes) . 
The  slowness  of  the  constricting  phase  is  to  be  accounted 
for  by  fatigue  of  the  constrictor  mechanisms.  Anderson, 
after  eliminating  the  dilator  paths,  saw  similar  evidence 
of  fatigue  in  eliciting  the  sensory  reflex.  Repeated 
stimuli  were  without  effect  unless  an  interval  of  some 
minutes  was  allowed. 


m  SEMICIRCULAR  CANALS 

The  foregoing  explanation  of  liippns  implies  the  exist- 
ence of  final  common  paths  which  unite  the  dilator  and 
constrictor  effectors  in  associated  action.  The  co-ordina- 
ting centre  is  situated  at  the  commencement  of  these  asso- 
ciated final  common  paths  somewhere  in  the  cerebellum  or 
mid-brain.  As  the  simple  reflex  has  been  amalgamated 
with  other  reflexes  to  make  the  type  reflex,  so  the  pupil 
reflex  in  certain  cases  has  been  compounded  with  other 
nociceptive  reflexes  to  form  complicated  protective  move- 
ments. We  have  already  seen  that  the  simple  direct  con- 
nection between  the  oculo-motor  and  vestibular  nuclei  is 
not  sufficient  to  insure  co-ordinated  action  between  ocular 
movements  and  movements  of  equilibration.  A  higher 
co-ordinating  centre  is  necessary.  Similarly,  in  certain 
phases  at  least,  the  pupil  reflex  seems  to  require  some 
higher  co-ordinating  centre,  exclusive  of  that  within  the 
third  nucleus.  Ferrier's^  observations  give  us  grounds 
for  locating  the  centres  for  reflex  ocular  movements  in  the 
cerebellum.  Ferrier's  experiments  also  seem  to  indicate 
that  there  are  pupillary  centres  in  the  cerebellum  asso- 
ciated with  those  for  ocular  movements.  The  exact  loca- 
tion of  the  higher  pupillary  centres  is  a  matter  for  future 
research.  Meanwhile  it  is  justifiable  to  assume  their  ex- 
istence presumably  in  the  cerebellum  or  mid-brain,  judg- 
ing from  analogy  and  the  results  of  certain  experiments 
in  relation  to  the  spinal  reflexes.  The  paths  described 
by  v.  Bechterew  as  passing  in  the  superior  peduncle  be- 
tween the  third  nucleus  and  the  cerebellum  are  probably 
related  to  this  higher  representation  of  pupillary  move- 
ments.    See  superior  peduncle  in  the  anatomical  synopsis. 

The  possibility  of  alternating  vascular  changes,  coinci- 
dent with  similar  changes  in  the  general  circulation,  caus- 
ing the  hippus  phenomena,  may  be  dismissed  since  the 
range  and  suddenness  of  the  iris  movements  were  alto- 
gether beyond  the  capacity  of  mere  vascular  variations. 

The  constriction  of  the  pupils  so  regularly  seen  in  aural 
irrigations  results,  to  some  extent  perliaps,  rather  from  the 
prolonged  constrictor  phase  of  the  hippus  than  from  any 
constrictor  effect  attrilnitable  to  vestibular  irritation.  The 
inequality  of  the  pupils  n^sults  from  relative  or  absolute 
increase  of  cerebellar  tonus  in  one  side  as  compared  with 
the  other.      Ferrier  ^  has  shown  that  stimulation  of  one 


PHYSIOLOGY  261 

side  of  the  cerebellum  causes  homolateral  pupillary  con- 
striction. In  cold  irrigations  of  the  left  ear  the  labyrin- 
thine receptors  are  depressed.  As  these  receptors  are 
mainly  related  to  the  opposite  half  of  the  cerebellum  there 
is  depression  of  cerebellar  tonus  upon  the  right  side  with 
a  relative  increase  of  it  on  the  left  side.  This  causes  the 
relative  constriction  in  the  left  pupil  found  so  constantly 
in  cold  irrigations  in  the  left  ear.  Similarly  in  hot  irri- 
gations in  the  left  ear  the  cerebellar  tonus  is  increased 
upon  the  opposite  side,  causing  relative  constriction  of 
the  right  pupil. 

The  first  effect  of  hot  and  cold  irrigations  upon  the 
retinal  vessels  was  dilatation.  This  was  immediately  fol- 
lowed by  marked  contraction.  When  the  irrigations  were 
continued  until  nausea,  sickness  and  general  exhaustion 
resulted,  the  retinal  vessels  were  in  a  state  of  extreme 
contraction,  the  dark  shadows  from  the  chorioidal  vessels 
showing  plainly  through  the  pale  retina.  A  short  time 
after  the  irrigations  the  retinal  vessels  were  regularly  some- 
what dilated.  At  times  the  subject  saw  coloured  images, 
evidently  shadows  from  the  disc  and  retinal  vessels.  Irri- 
gations at  100°  F.  caused  the  retinal  vessels  to  dilate. 

These  observations  correspond  closely  with  those  made 
by  Rockwell  and  Beard  ^° '^  upon  galvanization  of  the  sympa- 
thetic in  the  neck.  Roosa,  who  held  the  ophthalmoscope, 
saw  at  first  hypersemia  of  the  retinal  vessels  followed  soon 
by  anaemia.  However,  much  difference  of  opinion  exists 
between  observers  as  to  the  precise  changes  in  the  retinal 
vessels  that  follow  galvanization  of  the  sympathetic.  Some 
saw  only  contraction,  whilst  others  saw  only  dilatation. 
Perhaps  the  difference  in  the  findings  is  due  to  a  differ- 
ence in  the  strength  of  the  stimulus  and  a  difference  in  the 
time  of  observation  as,  after  a  certain  length  of  time  (a 
few  moments)  following  aural  irrigations,  the  retinal  ves- 
sels became  dilated.  The  constriction  and  dilatation  of 
the  retinal  vessels  during  rotations  and  irrigations  seem 
to  be  but  a  part  of  the  general  circulatory  changes  in  prog- 
ress during  rotations  and  irrigations,  and  seem  to  be 
caused  by  alternate  excitation  and  inhibition  of  the  vaso- 
constrictor centre  by  stimuli  originating  in  the  labyrin- 
thine, cardiac  and  other  receptors. 

The  visual  fields  did  not  seem  to  be  affected  in  any  par- 


262  SEMICIRCULAR  CANALS 

ticiilar  manner  by  aural  irrigations,  but  no  adequate  tests 
were  made  uj)on  which  to  base  reliable  conclusions  as  to 
this  point. 

The  apparent  movements  of  objects  during  the  after- 
nystagmus  in  rotations  and  during  the  nystagmus  of  au- 
ral irrigations  needs  a  little  further  elucidation.  It  has 
already  been  explained  that  in  horizontal  nystagmus,  say 
toward  the  right,  vision  is  impossible  during  the  excur- 
sions of  the  fundus  to  the  left  under  the  influence  of  the 
short  jerky  elements  of  the  anterior  part  of  the  eyeball  to 
the  right.  Vision,  however,  is  possible  during  the  slow 
return  movements  of  the  fundus  toward  the  right.  It  is 
owing  to  this  slow  return  movement  that  images  of  exter- 
nal objects  fall  upon  successive  horizontal  areas  of  the 
retina  which  are  nearer  and  nearer  to  the  left  of  the  fun- 
dus. This  movement  of  images  upon  the  retina  toward 
the  left  is  falsely  interpreted  (projected)  as  a  movement  of 
external  objects  toward  the  right.  See  diagrams.  A  simi- 
lar explanation  holds  for  vertical  nystagmus. 

In  rotary  nystagmus,  vision  is  likewise  impossible  dur- 
ing the  rapid  excursions  at  the  height  of  the  nystagmus. 
During  the  slow  return  movement,  however,  vision  is  clear. 
Thus  in  rotary  nystagmus  against  the  watch,  the  slow 
movement  of  the  fundus  occurs  with  the  watch.  During 
such  a  movement  objects  directly  in  front  of  the  eyes 
casting  their  images  directly  on  the  centre  of  the  retina 
do  not  seem  to  move,  whilst  objects  to  the  left  of  the  sub- 
ject appear  to  move  upward  from  the  feet  to  the  head  and 
those  on  his  right  seem  to  move  downward  from  the  head 
toward  the  feet.  The  explanation  is  as  follows:  The 
images  of  objects  situated  on  the  subject's  left  appear  on 
the  right  side  of  the  retina  at  successively  lower  levels, 
owing  to  the  slow  return  movement  of  the  fundus  with 
the  watch.  This  is  falsely  interpreted  (projected)  as  an 
actual  movement  of  the  external  objects  from  below  up- 
ward. See  diagram.  Objects  situated  on  the  right  of 
the  subject  cast  their  images  upon  the  left  side  of  the 
retina.  Owing  to  the  slow  movement  of  the  retina  with 
the  watch  the  images  appear  at  successively  higher  levels 
on  the  retina.  This  is  falsely  interpreted  as  an  actual 
movement  of  external  objects  from  above  downward.  For 
similar  reasons  looking  downward  in  rotary  nystagmus 


PHYSIOLOGY  263 

against  the  watch  gives  the  appearance  of  external  objects 
moving  toward  the  left,  whilst  looking  upward  gives  the 
impression  of  an  apparent  movement  of  objects  toward 
the  right.  It  should  be  remembered,  however,  that  vol- 
untarily turning  the  eyes  strongly  in  certain  directions 
has  a  tendency  to  inhibit  or  enhance  one  or  other  element 
of  the  nystagmus.  Thus,  for  instance,  looking  upward  fre- 
quently slows  or  inhibits  the  rapid  element  in  rotary  nys- 
tagmus against  the  watch  and  at  the  same  time  may  de- 
velop a  vertical  nystagmus  in  an  upward  direction.  On 
account  of  the  location  of  their  insertions  in  relation  to  the 
centre  of  rotation  of  the  eyeball  the  superior  and  inferior 
oblique  muscles  tend  to  rotate  the  globe  downward 
(Fuchs  ^°°) .  Hence,  looking  up  tends  to  inhibit  the  play 
of  these  muscles  in  nystagmus  and  thereby  to  favor  the 
development  of  some  latent  or  subsidiary  form  in  another 
direction. 

The  general  effect  of  a  mixed  horizontal  and  rotary  nys- 
tagmus to  the  right  and  against  the  watch  respectively,  is 
ordinarily  the  appearance  of  external  objects  moving  from 
left  to  right  with  a  downward  slant. 

The  nystagmus  of  aural  irrigations  has  already  been 
described.  In  rotations  about  the  three  main  axes  of  the 
body  a  characteristic  dominant  type  of  nystagmus  was 
found  to  be  constant  for  the  movement  in  each  separate 
plane.  Thus  rotation  about  the  long  axis  from  right  to 
left  has  directly  associated  with  it  a  primary  horizontal 
nystagmus  directed  toward  the  left;  rotation  in  the  mesial 
plane  "face  first"  has  directly  associated  with  it  vertical 
nystagmus  directed  toward  the  feet,  whilst  rotation  in  the 
mesial  plane  "occiput  first"  has  directly  associated  with 
it  vertical  nystagmus  directed  toward  the  top  of  the  head. 
In  addition  to  the  dominant  form  of  nystagmus,  however, 
there  was  at  times  present  in  the  various  forms  of  rota- 
tion a  subsidiary  form.  Thus  in  rotations  about  the  long 
axis  from  right  to  left  a  rotary  nystagmus  with  the  watch 
was  superadded  to  the  primary  horizontal  nystagmus 
directed  to  the  left. 

The  actual  movements  of  the  eyes  were,  of  course,  best 
studied  in  the  after-nystagmus,  and  deductions  made 
from  these  as  to  the  primary  movements  as  well  as  from 
the  apparent  movernent  of  external  objects.     The  domi- 


264  SEMICIRCULAR   CANALS 

nant  element  of  nystagmus  was  also  directly  observed 
during  actual  rotations.  In  aural  irrigations  the  direction 
of  the  elements  of  the  nystagmus  was  directly  ascertained 
by  the  aid  of  the  ophthalmoscope  and  was  found  to  justify 
the  deductions  already  made  in  rotations.  The  cause  of 
the  mixed  type  of  nystagmus  in  rotations  was  due  in  part 
to  an  irregularity  in  the  direction  of  the  swing  whereby  the 
body,  instead  of  revolving  strictly  about  its  long  axis,  de- 
scribed in  its  course,  as  a  whole,  an  ellipse,  thus  approxi- 
mating a  movement  to  and  fro  in  the  coronal  plane,  thereby 
affecting  the  receptors  in  the  ampullae  of  the  superior 
canals.  In  aural  irrigations  a  great  factor  in  the  production 
of  the  superadded  rotary  element  is  to  be  sought  in  the 
anatomical  relations  of  the  semicircular  canals,  whereby 
the  prolonged  action  of  heat  or  cold  affects  not  only  the 
receptors  in  the  ampulla  of  the  external  semicircular  canal, 
but  also  the  receptors  in  the  nearby  ampulla  of  the  superior 
canal,  and  even  those  in  the  macula  of  the  utricle.  In 
rotations  in  the  coronal  plane,  the  chief  effect  of  which  is 
felt  in  one  or  other  of  the  ampullae  of  the  superior  semi- 
circular canals,  a  secondary  and  subsidiary  effect  is  fre- 
quently manifested  through  the  ampullary  receptors  of 
the  adjacent  horizontal  canal. 

In  rotations  in  the  mesial  plane  the  peripheral  laby- 
rinthine mechanisms  involved  are  bilateral  instead  of  uni- 
lateral as  in  rotations  in  the  coronal  plane  or  about  the 
long  axis.  Thus  in  rotations  in  the  mesial  plane  "occi- 
put first"  the  ampullae  of  both  posterior  canals  are  chiefly 
affected,  whilst  their  natural  opponents  in  rotations  in 
the  mesial  i^lane,  viz.,  the  ampullie  of  both  superior  canals 
are  chiefly  affected  in  rotations  "face  first."  In  rotations 
in  the  mesial  plane  the  nystagmus  is  almost  purely  verti- 
cal being  primarily  directed  toward  the  feet  in  rotations 
"face  first"  and  toward  the  vertex  capitis  in  rotations 
"occiput  first."  If  the  rotations  be  confined  strictly  to 
the  sagittal  plane  no  horizontal  or  rotary  element  will  ap- 
pear in  normal  individuals,  because  under  the  conditions 
supposed  the  ampullae  of  each  pair  of  canals  are  equally 
affected,  for  in  mesial  rotations  the  ampulla  of  one  canal 
upon  one  side  is  not  opposed  functionally  to  its  fellow  of 
the  opposite  side,  as  in  coronal  and  horizontal  rotations, 
but  both  ampullae  of  the  superior  canals  are  the  direct 


PHYSIOLOGY  265 

opponents  of  both  ampullse  of  the  posterior  canals.  Since, 
therefore,  horizontal  and  rotary  nystagmus  are  caused 
respectively  by  unilateral  affection  of  a  horizontal  or  a 
superior  canal  respectively,  it  is  clear  that  in  mesial  rota- 
tions these  elements  are  generally  absent.  Here,  again, 
aural  irrigations  have  come  to  the  rescue,  for  whilst  hori- 
zontal and  rotary  nystagmus  occur  simultaneously  in  one- 
sided hot  and  cold  irrigations,  when  such  irrigations  were 
given  bilaterally  and  with  care,  the  only  nystagmus  pro- 
duced was  of  the  vertical  type.  In  the  case  of  bilateral 
cold  irrigations  the  vertical  nystagmus  was  directed  toward 
the  head,  as  directly  observed  by  means  of  the  ophthalmo- 
scope. As  this  form  of  nystagmus  is  the  same  as  that 
which  directly  accompanies  rotations  in  the  mesial  plane 
"occiput  first"  and  as  bilateral  cold  irrigations  act  by 
depressing  equally  the  receptors  in  the  ampullae  of  the 
superior  and  horizontal  canals  of  both  sides  which,  as  we 
have  just  seen,  has  no  effect  or  a  neutral  one  in  causing 
horizontal  and  rotary  nystagmus,  it  is  evident  that  the 
vertical  nystagmus  toward  the  vertex  must  result  from  a 
disturbance  of  the  mechanisms  involved  in  mesial  rota- 
tions, viz. ,  by  means  of  absolute  depression  of  irritability 
(increased  threshold  value)  of  the  receptors  in  the  am- 
pullae of  the  superior  canals  or,  which  amounts  to  the  same 
thing,  a  relative  enhancement  of  irritability  (lowered 
threshold  value)  in  the  receptors  of  the  ampullae  of  the 
posterior  canals. 

In  bilateral  hot  irrigations  the  vertical  nystagmus  is 
directed  toward  the  feet.  In  these  irrigations  the  periph- 
eral mechanisms  involved  in  mesial  rotations  were  dis- 
turbed by  enhancement  of  irritability  (lowered  threshold 
value)  in  the  receptors  of  the  ampullae  of  the  superior 
canals,  resulting  in  nystagmus  that  is  identical  in  nature 
and  direction  with  that  which  is  directly  associated  with 
mesial  rotations  "face  first."  In  this  way,  by  means  of 
aural  irrigations,  a  knowledge  of  the  function  of  the  pos- 
terior canals  has  been  obtained,  even  though  they  are  too 
deeply  situated  to  be  directly  affected  by  heat  or  cold  ap- 
plied within  the  external  auditory  canal.  And  this  knowl- 
edge accords  in  every  respect  with  what  has  been  deter- 
mined by  animal  experimentation.  Ewald,  ^^  by  means 
of  his  pneumatic  hammer,  and  Breuer,  '^  by  means  of  sue- 


266  SEMICIRCULAR  CANALS 

tion  and  insufflation,  found,  on  forcing  the  endolymph 
toward  the  ampulla  of  the  horizontal  canal,  a  stimulus 
reaction  in  which  the  head  went  to  the  opposite  side  and 
on  withdrawal  of  the  hammer  a  weaker  reaction  of  retarda- 
tion caused  by  the  current  of  endolymph  from  the  am- 
pulla toward  the  canal.  The  stimulation  effect  obtained 
thus  by  Ewald  from  a  current  of  endolymph  toward  the 
ampulla  corresponds  exactly  with  those  effects  obtained 
from  hot  irrigations  on  one  side  or  directly  from  rotation 
about  the  long  axis  toward  the  side  in  which  the  canal 
under  observation  is  located.  Ewald 's  experiment  shows 
conclusively  that  in  rotations  about  the  long  axis  the  chief 
effect  upon  the  ampullary  nerve  endings  is  brought  about 
by  whatever  tends  to  create  a  current  of  endolymph 
toward  the  ampulla  from  the  canal,  and  that  a  secondary 
retardation  effect,  much  less  in  degree,  is  to  be  expected 
from  whatever  tends  to  create  a  current  of  endolymph  from 
the  ampulla  toward  the  canal.  Owing  to  the  fact  that 
the  calibre  of  the  membranous  canals  is  capillary  in  size, 
an  actual  movement  of  the  endol}miph  from  the  ampulla 
toward  the  canal  is  scarcely  possible  in  rotations  calcu- 
lated to  cause  a  flow  of  endolymph  in  that  direction.  An 
alteration  of  pressure  conditions,  if  not  an  actual  move- 
ment of  endolymph,  is  sufficient  to  stimulate  the  ampullary 
receptors  so  as  to  upset  the  delicate  balance  of  the  laby- 
rinthine tonus  apparatus.  The  delicacy  of  the  ampullary 
receptors  is  extreme.  All  sorts  of  stimuli  seem  to  affect 
them,  e.g.,  galvanic,  tactual,  thermal,  and  even  photo 
stimuli. 

Looking  now  to  the  location  and  direction  of  the  semi- 
circular canals  and  their  relations  to  each  other  it  is  evi- 
dent that  in  a  rotation  about  the  long  axis,  let  us  say  from 
left  to  right,  there  is  created  in  the  right  horizontal  canal 
a  tendency  to  drive  the  endolymph  toward  the  ampulla 
from  the  canal,  and  if  the  subject's  head  be  tilted  back- 
ward at  the  same  time,  there  is  created  in  the  left  superior 
canal  a  tendency  for  the  endolymph  to  flow  from  the  am- 
pulla toward  the  canal.  In  rotations  in  the  mesial  plane 
"occiput  first"  there  is  a  tendency  to  drive  the  endolymph 
away  from  the  ampullae  of  both  posterior  canals,  causing 
vertical  nystagmus  toward  the  vertex.  In  mesial  rotations 
"face  first"  there  is  a  tendency  to  drive  the  endolymph 


PHYSIOLOGY  267 

away  from  the  ampullae  of  both  superior  canals  with  the 
production  of  vertical  nystagmus  toward  the  feet.  The 
absence  of  rotary  nystagmus  in  these  mesial  rotations  is 
accounted  for  by  the  simultaneous  and  equal  affection  of 
the  opposing  sets  of  receiptors  upon  either  side  of  the  body. 
The  views  here  expressed  have  the  support  of  Ewald,'^  w^ho 
found  that  whereas  a  flow  of  endol}Tiiph  toward  the  am- 
pulla from  the  canal  caused  the  stimulus  reaction  in  the 
horizontal  canal,  the  opposite  was  true,  for  the  superior 
and  posterior  canals  in  which  the  flow  from  the  ampullae 
toward  the  canals  had  the  primary  stimulating  effect, 
whilst  a  flow  toward  the  ampullae  caused  the  weaker  re- 
action of  retardation. 

In  rotations  against  the  watch  in  the  coronal  plane  with 
the  subject  lying  supine,  the  mixed  after-nystagmus  was 
composed  of  a  rotary  element  with  the  watch  and  a  verti- 
cal element  directed  toward  the  feet.  External  objects 
seemed  to  move  from  the  head  toward  the  feet  in  a  slant- 
ing direction,  roughly  indicated  by  a  line  drawn  from  the 
left  eye  to  the  right  great  toe.  By  stopping  the  swing 
suddenly,  a  current  of  endolymph,  away  from  the  ampulla, 
was  created  in  the  left  superior  canal,  thereby  causing  the 
after-nystagmus  just  described.  The  apparent  movement 
of  objects  in  this  instance  evidently  resulted  from  enhance- 
ment of  the  downward  vertical  element  due  to  the  peculi- 
arities of  insertion  of  the  superior  and  inferior  oblique 
muscles.  This  element  is  normally  latent  in  pure  rotary 
nystagmus,  but  may  be  developed  by  looking  toward  the 
feet. 

Whether  the  tendency  to  a  reflux  toward  the  canal  from 
the  ampulla,  or  vice  versa,  is  important  in  determining  the 
secondary  nystagmus  and  other  effects,  seems  doubtful, 
since  the  conditions  in  rotations  as  the  swing  slows  down, 
can  hardly  be  compared  with  those  brought  about  by 
Breuer's  suction  or  by  stripping  the  membranous  canals 
by  means  of  the  Ewald  hammer.  At  all  events  the  ten- 
dency to  positive  counterpressures,  created  in  the  canals  of 
the  opposite  side  by  slowing  or  stopping  of  the  swing, 
overshadows  such  retardation  effects. 


CHAPTER  XVIII 

THE   EFFECTS    OF  THE   GALVANIC    CURRENT   UPON 
THE   SEMICIRCULAR   CANALS 

Numerous  observations  were  made  on  various  subjects 
and  with  the  anode  and  cathode  in  various  positions,  such, 
for  instance,  as  with  one  electrode  over  the  mastoid  area 
whilst  the  other  was  held  in  the  hand  of  the  same  or  oppo- 
site side,  or  fixed  upon  the  breast.  All  sort.s  of  combina- 
tions were  tried.  The  electrode  applied  to  the  mastoid 
area  was  held  in  position  by  a  bandage  the  better  to  ap- 
preciate the  smaller  degrees  of  reactionary  movements  of 
the  head. 

The  general  results  were  as  follows :  With  the  positive 
pole  over  the  left  and  the  negative  over  the  right  mastoid 
area,  the  head  went  strongly  to  the  left  side  on  closure  of 
the  circuit.  The  eyes  were  at  first  drawn  to  the  left  side 
but  later  showed  mixed  nystagmus,  the  horizontal  element 
being  directed  to  the  right  and  the  rotary  element  directed 
against  the  watch.  External  objects  seemed  to  move  from 
left  to  right  and  downward.  The  retinal  vessels  were  at 
first  dilated  and  later  contracted.  There  were  vertigo, 
pallor,  nausea,  "lump-sensation' '  in  the  stomach,  increased 
saliva,  etc.  In  fact  the  phenomena  were  in  every  way 
analogous  to  those  seen  with  cold  irrigations  of  the  left 
ear. 

On  opening  the  circuit  the  head  was  immediately  pulled 
toward  the  right,  i.e.,  into  the  vertical  position.  With 
the  anode  over  the  left  mastoid  and  the  cathode  over  the 
left  breast  similar  phenomena  were  observed,  but  of  less  de- 
gree. With  the  cathode  over  the  left  mastoid  area  and 
the  anode  over  the  left  breast  the  head  was  drawn  to  the 
right  on  closure  of  the  circuit,  and  the  eyes  showed  mixed 
nystagmus,  the  horizontal  element  being  toward  the  left, 
whilst  the  rotary  element  was  with  the  watch.     These 

268 


PHYSIOLOGY  269 

movements  of  the  head  and  eyes  were  of  greater  degree 
than  the  similar  movements  noted  with  the  positive  pole 
over  the  left  mastoid.  The  reaction  of  the  cathode  over 
the  left  mastoid  area  was  in  every  respect  analogous  to  a 
hot  irrigation  of  the  left  ear. 

During  the  continued  flow  of  the  current,  if  the  subject 
closed  his  eyes  he  felt  his  body  revolving  about  its  long 
axis  in  the  same  direction  as  that  taken  by  the  horizontal 
element  of  the  nystagmus.  Let  us  suppose  the  case  where 
the  anode  is  over  the  left  mastoid  and  the  head  inclines  to 
the  left,  whilst  the  eyes  are  in  nystagmus  with  the  horizontal 
element  toward  the  right.  If  the  subject  close  his  eyes  he 
will  imagine  himself  revolving  about  his  long  axis  from 
left  to  right.  This  is  exactly  what  the  subject  experiences 
sitting  upright  with  closed  eyes  during  a  cold  irrigation 
of  the  left  ear.  It  is  also  the  counterpart  of  what  occurs 
upon  sudden  slowing  or  stopping  of  a  rotation  about  the 
long  axis  from  right  to  left. 

A  male  subject,  aged  55,  afflicted  with  tabes  dorsalis,  but 
with  normal  hearing,  showed  the  usual  reaction  to  galvan- 
ism. On  standing  up  the  disturbances  of  equilibrium  on 
opening  and  closing  the  circuit  were  very  marked.  This 
subject  seemed  more  susceptible  to  galvanic  vertigo  than 
the  usual  run  of  people.  After  the  application,  which  was 
very  mild  and  did  not  sicken  or  distress  him  as  did  irri- 
gations practised  on  a  previous  occasion,  it  was  noted  that 
for  a  time  the  subject  walked  and  balanced  better  than 
before  the  application. 

In  a  normal  person  the  anode  and  cathode  were  care- 
fully secured  over  the  left  and  right  mastoid  areas  respec- 
tively, and  careful  note  was  made  of  the  degree  of  response 
made  on  closure  of  the  circuit  as  measured  by  the  devia- 
tion of  the  head  and  body. 

A  bilateral  aural  irrigation  at  121°  F.  was  then  given, 
with  the  electrodes  still  in  situ  and  immediately  after  the 
irrigation  the  circuit  was  closed.  It  was  found  that  after 
the  hot  irrigation  the  reaction  was  markedly  increased, 
the  head  and  body  going  much  more  strongly  toward  the 
anode.  In  addition  the  susceptibility  of  the  subject  was 
otherwise  enhanced,  for  the  current,  after  the  irrigation, 
made  him  feel  nauseated  and  much  sicker  and  dizzier  than 
it  had  ever  done  before,  so  that  he  became  very  pale, 


270  SEMICIRCULAR  CANALS 

weak  and  tremulous.  Care  was  taken  to  use  currents  of 
equal  strength  in  each  case  and  to  eliminate  every  possible 
source  of  error.  It  was  noted  that  the  increased  irritabil- 
ity to  galvanism  of  the  semicircular  canals  soon  dis- 
appeared. 

With  the  cathode  over  the  left  and  the  anode  over  the 
right  mastoid  area,  tests  were  carefully  made  before  and 
after  irrigation  of  the  left  ear  at  115°  F.  It  was  noted 
that  after  the  irrigation  there  was  markedly  increased  de- 
viation of  the  head  to  the  right  on  closure  of  the  circuit. 
The  hot  irrigation  also  caused  gradually  ■  increasing  pain 
in  the  vicinity  of  the  drum  membrane  until  the  flow  of 
water  became  unbearable. 

Similar  tests  were  made  with  the  cathode  over  the  left 
mastoid  and  the  anode  over  the  left  breast.  It  was  noted 
that  after  irrigation  of  the  left  ear  at  115°  F.  the  deviation 
to  the  right  was  increased  on  closure  of  the  circuit  com- 
pared with  that  noted  before  the  irrigation.  With  the 
cathode  still  over  the  left  mastoid  it  was  found,  after  irri- 
gation of  the  right  ear  with  water  at  115°  F.  that  devia- 
tion to  the  right  was  diminished  or  absent  on  closure  of 
the  circuit.  Currents  of  equal  strength  were  used  before 
and  after  the  irrigation. 

Similar  tests  were  made  with  the  anode  over  the  left 
mastoid  and  the  cathode  over  the  left  breast.  After  irri- 
gation of  the  left  ear  at  115°  F.  there  was  no  deviation 
on  closure  of  the  circuit.  Immediately  the  position  of  the 
poles  was  reversed  so  that  the  cathode  was  placed  over  the 
left  mastoid  and  then  closure  of  the  circuit  resulted  in  a 
marked  deviation  to  the  right.  It  was  noted  that  if  these 
tests  were  made  with  the  subject  standing  up,  the  dis- 
turbance of  equilibrium  was  much  more  manifest  and  the 
subject's  sickness,  nausea,  etc.,  more  pronounced  than 
when  tlie  tests  were  made  with  the  subject  sitting  erect. 
After  the  last  hot  irrigation  the  subject  deviated  to  the 
right  in  walking  with  the  eyes  closed. 

Galvanism  was  tried  on  a  man  25  years  old  in  whom 
there  was  practically  no  drum  membrane  in  the  left  ear, 
whilst  there  were  two  fair-sized  perforations  in  the  right 
drum  membrane.  It  was  at  once  apparent  that  this  man  was 
unusually  susceptible  to  the  effects  of  galvanism  as  com- 
pared with  all  the  other  subjects  examined.     It  should  be 


PHYSIOLOGY  271 

mentioned,  however,  that  previous  to  the  application  of 
the, electrodes  he  had  had  cold  and  hot  irrigations,  the  last 
one  being  at  116°  F.  With  the  anode  over  the  left,  and 
the  cathode  over  the  right  mastoid  area  and  properly 
secured,  on  closure  of  the  circuit  the  head  inclined  to  the 
left.  The  eyes  were  at  first  drawn  to  the  left  and  w^ere 
rotated  strongly  in  the  direction  of  the  hands  of  the  watch. 
It  was  soon  apparent,  however,  that  a  mixed  nystagmus 
was  present,  with  the  horizontal  element  directed  to  the 
right,  and  the  rotary  element,  which  was  unusually  well 
marked,  directed  against  the  watch.  During  the  continu- 
ance of  the  current  this  nystagmus  persisted  to  the  right 
and  against  the  watch.  During  the  continued  flow  of  the 
current  on  turning  the  eyes  strongly  to  the  left  the  rapid 
jerks  of  the  rotary  nystagmus  seemed  to  be  lengthened  and 
slowed,  and  external  objects  seemed  to  move  up  and  down. 
On  looking  up  there  seemed  to  be  less  motion  of  the  eyes, 
and  what  motion  there  was  took  place  in  the  horizontal 
plane  to  the  right.  External  objects  seemed  to  move  in 
the  same  plane  and  direction.  On  looking  down,  the 
rotary  element  was  still  against  the  watch,  and  objects 
seemed  to  jump  from  side  to  side.  On  looking  to  the 
right  the  eyes  jerked  to  the  right  and  against  the  watch. 
On  looking  to  the  left  moderately,  the  eyes  jerked  mainly 
against  the  watch,  and  objects  appeared  to  go  upward  on 
the  left. 

At  the  moment  of  "making"  with  the  eyes  directed  to 
the  right,  the  eyeballs  were  drawn  to  the  left  and  rotated 
with  a  steady  pull  in  the  direction  of  the  hands  of  the 
watch.  On  looking  to  the  left  at  the  moment  of  ' '  making' ' 
the  eyes  were  rotated  strongly  with  the  watch.  On  looking 
up  and  on  looking  down,  the  eyes  were  similarly  drawn 
to  the  left  and  rotated  with  the  watch  at  the  moment  of 
closure  of  the  circuit.  With  the  anode  over  the  right,  and 
the  cathode  over  the  left  mastoid  area,  similar  phenomena 
were  noted.  The  head  inclined  to  the  right.  There  was 
mixed  nystagmus  with  the  horizontal  element  to  the  left 
and  the  rotary  element  with  the  watch.  Objects  seemed 
to  pass  around  the  subject's  body  in  the  direction  of  the 
hands  of  the  watch  in  the  coronal  plane. 

The  conclusions  are: 

1.  That  the  effects  of  closure  of  the  circuit  with  the 


272  SEMICIRCULAR   CANALS 

anode  over  the  left  mastoid  are  exactly  like  those  of  cold 
irrigations  of  the  left  ear  which,  in  turn,  are  like  the 
primary  effects  of  rotation  about  the  long  axis  from  left 
to  right  or  the  secondary  effects  of  a  similar  rotation  from 
right  to  left. 

2.  That  the  effects  of  closure  of  the  circuit  with  the 
cathode  over  the  left  mastoid  area  are  identical  with  those 
of  hot  irrigations  in  the  left  ear,  and  with  the  primary 
effects  of  rotation  from  right  to  left  about  the  long  axis  or 
the  secondary  effects  of  a  similar  rotation  from  left  to 
right. 

3.  That  on  closure  of  the  circuit  with  the  anode  over 
the  left,  and  the  cathode  over  the  right  mastoid  area,  the 
effect  is  enhanced,  just  as  in  the  case  of  simultaneous  irri- 
gation of  the  two  ears  with  water  at  79°  F.  in  one  ear, 
and  107°  F.  in  the  other,  after  it  had  been  shown  that 
single  irrigations  at  either  one  of  these  temperatures  was 
without  manifest  effect. 

4.  That  hot  irrigations  affect  the  labyrinthine  receptors 
in  such  a  way  that  with  the  cathode  over  the  mastoid  area 
on  the  side  of  the  irrigation  the  usual  effect  is  enhanced, 
whilst  with  the  anode  over  the  mastoid  of  the  side  of  the 
irrigation  no  effect  is  manifested  or  experienced  by  the 
subject. 

5.  That,  as  a  corollary  to  No.  4,  hot  irrigations  act  by 
increasing  the  irritaljility  of  the  homolateral  ampullary 
receptors,  just  as  cold  irrigations  act  by  depressing  them. 


CHAPTER  XIX 

HOW    ROTATIONS,    AURAL   IRRIGATIONS,    AND   GAL- 
VANISM AFFECT  THE  LABYRINTHINE  RECEPTORS 
AND   THE   RELATED   EFFECTORS 

It  has  already  been  shown  that  in  rotations  the  chief 
effect  upon  the  ampullary  receptors  is  caused  by  changes 
of  pressure  conditions  resulting  from  a  tendency  of  the 
endolymph  to  flow  in  a  particular  direction,  e.  g. ,  toward 
the  ampulla  in  the  case  of  the  horizontal  canals,  and  away 
from  the  ampulla  in  the  case  of  the  superior  and  posterior 
canals.  The  experiments  of  Ewald^^  and  of  Breuer,^^  by 
stripping,  insufflation  and  suction  of  the  membranous 
canals,  were  cited  in  this  connection.  Furthermore  it  has 
been  shown  that,  with  the  subject  in  the  erect  posture, 
labyrinthine  balanced  mechanisms  exert,  constantly,  a  re- 
flex tonus  upon  part  at  least  of  the  muscles  involved  in 
equilibration  and  that  enhancement  or  depreciation  of  the 
irritabilty  of  the  labyrinthine  mechanisms,  or  of  part  of 
them,  upon  one  side  of  the  body  caused  disturbances  of 
equilibrium  and  nystagmus,  both  of  which  presented  a  con- 
stant characteristic  type  depending  upon  the  part  (canals) 
affected.  It  has,  moreover,  been  shown  that  cold  irriga- 
tions act  by  depressing  the  normal  irritability  of  the  am- 
pullary and  perhaps  the  macular  receptors,  whereby  the 
tonus  exerted  reflexly  through  the  related  nervous  arcs  is 
diminished  on  one  side,  thus  upsetting  the  reflex  balanced 
mechanisms  with  consequent  deviation  of  the  head  toward 
the  side  of  irrigation  and  horizontal  nystagmus  directed 
toward  the  opposite  side.  On  the  other  hand,  hot  irriga- 
tions act  by  increasing  the  irritability  of  the  labyrinthine 
receptors  affected,  thereby  disturbing  the  reflex  balanced 
mechanisms  with  deviation  of  the  head  to  the  opposite 
side  and  horizontal  nystagmus  directed  to  the  side  of  irri- 
gation     The  enhanced  or  depressed    irritability  of   the 

273 


274  SEMICIRCULAR   CANALS 

receptors  acts  by  increasing  or  diminishing  the  quantita- 
tive value  of  the  afferent  impulses  normally  generated  by 
movements  of  the  head,  rotations,  etc.  That  this  is  so 
the  following  experiment  seems  to  prove.  The  subject 
sitting  erect  was  rotated  about  the  long  axis  from  left  to 
right.  The  after-nystagmus  of  mixed  type  w^as  directed 
to  the  left  and  with  the  w^atch.  An  irrigation  of  the  left 
ear  for  4  minutes  at  68°  F.  was  now  given,  and  immedi- 
ately the  rotation  from  left  to  right  was  repeated.  On 
suddenly  arresting  the  motion  there  was  found  to  be  no 
after-nystagmus,  either  of  the  horizontal  or  rotary  type  to- 
ward the  left  or  with  the  watch.  On  looking  to  the  left, 
the  eyes  w^ere  steady,  wdth  a  tendency  to  rotate  rather  slowly 
against  the  watch.  With  the  eyes  held  straight  or  turned 
to  the  right,  there  w^as  a  violent  mixed  nystagmus  with 
the  horizontal  element  directed  to  the  right  and  the  rotary 
element  against  the  watch.  In  other  w^ords,  instead  of 
the  usual  after- nystagmus  appearing,  the  primary  nystag- 
mus persisted,  and  traces  of  it  were  found  for  over  two 
minutes  after  the  sudden  arrest  of  the  rotation.  This  also 
shows  conclusively  that,  in  the  sudden  reversal  or  slowing 
of  rotations  about  the  long  axis,  the  active  factor  in 
causing  after-nystagmus  and  the  associated  phenomena, 
is  not  the  tendency  to  reflux  on  the  part  of  the  endolymph 
from  the  ampulla  toward  the  canal  upon  the  side  toward 
which  the  rotation  had  been  directed,  i.e.,  in  this  case  on 
the  right  side  but  a  positive  tendency,  created  by  the  sud- 
den cessation  of  the  rotation,  in  the  opposite  labyrinth  of 
the  endolymph  to  flow  from  the  canal  toward  the  ampulla. 
When  the  cold  irrigation  in  the  left  ear  had  deadened  the 
irritability  of  the  ampullary  receptors  of  the  left  horizon- 
tal and  superior  canals  the  pressure  conditions  created  by 
the  tendency  of  the  endolymph  to  flow  toward  or  away 
from  the  ampullse  were  without  effect.  In  this  manner 
the  usual  after-nystagmus  of  the  rotation  was  suppressed, 
and  the  primary  nystagmus  allowed  to  persist,  even  for 
some  minutes  after  the  rotation  had  been  suddenly  checked. 
At  a  later  period  this  subject  was  more  fully  studied. 
Rotations  in  various  i)lanes  were  given  inmiediately  after 
unilateral  and  bilateral  hot  and  cold  irrigations.  Bi^cause 
of  the  help  they  afford  in  determining  the  meclianism  of 
labyrinthine  phenomena  the  results  are  deemed  of  suiii- 


PHYSIOLOGY  275 

cient  importance  to  warrant  free  transcription  of  the  notes 
taken  during  the  experiments. 

With  the  subject  sitting  upright  in  the  swing,  bilateral 
aural  irrigation  at  54°  F.  caused  no  nystagmus  and  no  ap- 
parent movement  of  external  objects.  Immediately  after 
the  irrigation  a  brisk  rotation  was  given  about  the  long  axis 
from  right  to  left.  Upon  sudden  arrest  of  the  swing  there 
was  no  nystagmus  and  no  apparent  movement  of  external 
objects,  lout  the  subject  belched  violently  and  vomited 
mucus.  During  the  rotation  there  was  a  slight  feeling  of 
sickness  and  the  subject  could  see  external  objects  pass- 
ing before  his  eyes,  but  visual  fixation  was  impossible. 
It  was  noticeable  that  w^henthe  rotation  ceased  the  subject 
experienced  no  dizziness  or  distress  in  the  head,  did  not 
stagger  or  deviate  in  walking,  and  did  not  feel  weak  or 
want  to  lie  down,  whilst  the  external  world  seemed  steady 
and ' '  solid  as  a  rock. ' '  All  these  things  occurred  in  spite 
of  the  fact  that  stopping  the  swing  caused  violent  vomit- 
ing. The  subject,  however,  looked  very  pale  from  con- 
striction of  the  skin-vessels.  After  a  rest  of  25  minutes 
the  pulse-rate  and  blood-pressure  were  56  and  115  respec- 
tively. The  knee-jerks  were  fairly  active.  Bilateral  irri- 
gation at  54°  F.  caused,  just  after  its  commencement,  the 
blood-pressure  to  rise  to  130,  the  pulse  being  72.  After 
two  minutes  of  irrigation  the  pulse-rate  and  blood-pressure 
were  still  at  72  and  180  respectively.  There  was  no  nys- 
tagmus during  the  irrigation,  though  the  patient  felt  a  little 
sick  in  the  stomach.  Immediately  following  the  irriga- 
tion a  hard  swing  was  given  about  the  long  axis,  from  left 
to  right.  Abrupt  stopping  of  the  swing  did  not  cause 
distress  in  the  head  or  nystagmus.  There  was  no  apparent 
movement  of  external  objects,  but  again  the  subject 
belched  violently  and  vomited  bile-stained  mucus.  Im- 
mediately on  stopping  the  rotation  the  pulse-rate  and 
blood-pressure  were  60  and  185  respectively.  This  was  be- 
fore the  vomiting  had  occurred.  After  vomiting,  i.e.,  about 
one  minute  after  the  rotation,  the  pulse-rate  and  blood- 
pressure  were  80  and  140,  and  80  and  180,  whilst  the  knee- 
jerks  were  about  the  same  as  before  irrigation.  Five 
minutes  after  the  rotation  the  pulse-rate  and  blood-pressure 
were  64  and  115.  During  unilateral  irrigation  in  left  ear 
at  54°  F.  the  pulse-rate  and  blood-pressure  were  64  and 


276  SEMICIRCULAR  CANALS 

125,  and  there  was  present  an  irregular  vertical  nystag- 
mus, with  an  apparent  np  and  down  movement  of  objects. 
At  the  onset  of  the  irrigation  the  subject  felt  sick.  Just 
before  the  onset  of  vomiting  there  was  audible  gurgling 
in  the  stomach.  At  this  moment  the  pulse-rate  and  blood- 
pressure  were  76  and  125.  After  vomiting,  the  pulse-rate 
and  blood-pressure  were  84  and  145.  The  knee-jerks  were 
slightly  affected,  the  right  being  perceptibly  diminished. 
The  absence  of  horizontal  nystagmus  in  this  irrigation 
was  due  to  the  fact  that  the  ampullary  receptors  in  the  hori- 
zontal canals  had  not  recovered  from  the  effects  of  the 
previous  irrigations  (exhaustion) .  The  irregular  vertical 
nystagmus  was  due  to  a  rotary  element  caused  by  the 
effects  of  the  irrigation  upon  the  ampulla  of  the  left 
superior  canal.  It  was  noticed  that  with  the  unilateral 
irrigation  the  subject  broke  into  a  sweat  and  felt  very 
weak.  These  symptoms  were  absent  in  bilateral  irriga- 
tions. 

After  a  rest  the  subject  was  drowsy.  The  pulse-rate 
and  blood-pressure  were  56  and  110.  The  left  knee-jerk 
was  somewhat  more  active  than  the  right.  During  bilat- 
eral irrigation  at  115°  F.  there  was  slight  vertical  nystag- 
mus. The  subject  felt  dizzy  and  sick,  and  external  objects 
seemed  to  move  from  head  to  foot  and  a  little  toward  the 
right.  The  pulse-rate  and  blood-pressure  were  64  and 
180.  Rotations  about  the  long  axis  from  left  to  right  and 
from  right  to  left  were  rapidly  given  after  the  irrigation. 
Upon  checking  the  rotation  from  left  to  right  there  was 
horizontal  after-nystagmus  to  the  left.  Similarly,  upon 
checking  the  rotation  from  right  to  left,  there  was  horizontal 
after- nystagmus  to  the  right.  Each  rotation  made  the  sub- 
ject very  dizzy,  sick,  and  weak,  but  there  was  not  so  much 
tendency  to  vomit  as  after  the  previous  rotations.  This 
was  due  in  part  to  the  fact  that  the  stomach  had  been  so 
recently  emptied.  After  the  last  rotation,  which  was  from 
left  to  right,  the  subject  felt  very  distressed  in  the  head, 
and  external  objects  moved  rapidly  "in  a  flurry"  without 
any  particular  direction.  There  was  no  sweating  or  vomit- 
ing. The  knee-jerks  were  not  altered,  the  left  being  still 
slightly  stronger  than  the  right.  The  respiration  was 
heavy,  the  subject  complaining  that  he  felt  as  if  a  weight 
were  on  his  chest.     Immediately  following  the  first  swing, 


PHYSIOLOGY  m 

the  pulse-rate  and  blood-pressure  were  64  and  120.  Five 
minutes  after  the  last  rotation  the  subject  felt  "done  up. " 
His  eyes  were  tired  and  felt  like  closing.  The  pulse-rate 
and  blood-pressure  were  64  and  115. 

On  another  occasion  in  the  resting  state  the  pulse-rate 
and  blood-pressure  were  60  and  115.  During  irriga- 
tion of  the  left  ear  at  52°  F.  the  usual  horizontal  nystag- 
mus to  the  right  was  evident.  When  the  eyes  were  strongly 
turned  to  the  left,  there  were  jerky  rotary  movements 
against  the  watch.  With  the  eyes  open  and  turned  to  the 
left,  the  subject  felt  his  body  turning  on  its  long  axis 
from  left  to  right.  With  the  eyes  open  and  turned  to  the 
right,  the  subject  felt  his  body  rotating  to  the  right,  but 
not  so  much  so  as  when  his  eyes  were  turned  to  the  left. 
This  unusual  phenomenon  occurred  during  irrigations 
practised  with  the  subject  sitting  in  the  swing  with  the 
feet  off  the  floor,  and  is  interesting  because  it  shows  to 
what  an  extent  we  rely  upon  other  senses  for  corroboration 
of  labyrinthine  impressions  in  estimating  our  relations  in 
space.  When  the  subject  sat  upon  a  chair  with  the  feet 
upon  the  floor  and  with  the  eyes  open  and  turned  to  the  left, 
no  sense  of  motion  was  experienced  in  similar  irrigations. 
During  a  swing  from  right  to  left,  immediately  following 
irrigation  of  the  left  ear  at  52°  F.  the  subject  saw  external 
objects  as  a  streak.  Visual  fixation  was  impossible.  The 
tonus  required  for  the  slow  element  of  the  primary  nystag- 
mus was  wanting.  The  after-nystagmus  to  the  right  was 
violent,  the  eyes  oscillating  back  and  forth  with  excursions 
of  equal  length  and  duration,  and  highly  suggestive  of  the 
nystagmus  of  gross  cerebellar  defect.  Later  the  eyes 
steadied  down  somewhat  and  showed  slight  horizontal 
nystagmus  to  the  right.  At  first  during  the  after-nystag- 
mus, external  objects  seemed  to  move  back  and  forth 
furiously  from  side  to  side.  During  the  rotation  the  sub- 
ject could  hardly  think,  and  the  head  inclined  to  the  left 
shoulder  instead  of  to  the  right,  as  is  usual  in  rotations 
from  right  to  left.  There  was  no  dizziness,  and  external  ob- 
jects went  around  from  left  to  right.  Upon  cessation  of  the 
rotation  the  head  still  inclined  to  the  left  shoulder  and  the 
subject  felt  sick.  The  inclination  of  the  head  toward  the 
left  shoulder  during  the  rotations  is  a  further  proof  that  de- 
viations of  the  head  in  rotations,  aural  irrigations  and  gal- 


278  SEMICIRCULAR   CANALS 

vanism,  are  the  direct  result  of  changes  of  the  labyrinthine 
tonus  in  the  muscles  of  the  head  and  neck.  It  also  shows 
that  in  the  horizontal  canals,  stress  in  the  endolpnph  di- 
rected away  from  the  ampulla  is  not  a  factor  in  the  compen- 
sating movements  of  equilibration.  If  it  were  such  a  factor, 
then  during  the  rotation  from  right  to  left,  when  the  recep- 
tors in  the  ampulla  of  the  left  horizontal  canal  had  previ- 
ously been  deadened  by  cold  irrigation,  we  should  expect 
that  the  stress  in  the  endolpiiph  of  the  right  horizontal 
canal  away  from  the  amj^ulla  would  draw  the  head  toward 
the  right  shoulder.  The  evidence  pointed  merely  to  rela- 
tively increased  tonus  of  the  right  labyrinth  caused  by  de- 
pression of  the  receptors  in  the  left  labyrinth.  To  this 
and  this  alone,  must  be  attributed  the  deviation  of  the 
head. 

Irrigation  of  the  left  ear  at  50°  F.  given  10  minutes 
after  the  previous  irrigation,  caused  distress  in  the  stomach 
rather  than  in  the  eyes  or  head.  There  was  little  or  no 
nystagmus  even  in  turning  the  eyes  to  one  side  or  the 
other.  The  head  fell  toward  the  left  and  visual  fixation 
was  possible.  After  the  irrigation  a  hard  swing  from  left 
to  right  was  given.  During  the  swing  the  subject  vomited, 
and  the  head  fell  to  the  left  but  visual  fixation  was  ]30ssi- 
ble.  On  cessation  of  the  swing  the  head  still  fell  toward 
the  left.  There  was  no  after-nystagmus  on  looking  straight 
ahead  or  to  the  right.  There  was  a  slight  tendency  to 
horizontal  nystagmus  on  looking  toward  the  left.  From 
this  it  seems  that  the  tonus  innervation  associated  with 
the  slow  elements  is  the  important  factor  in  initiating 
nystagmus.  Thus,  upon  cessation  of  the  rotation,  stress 
of  the  endolymph  in  the  left  horizontal  canal  was  created 
toward  the  ampulla,  but  owing  to  the  depressed  condition 
of  the  receptors  (increased  threshold  value)  no  tonus  effect 
was  manifested  in  the  muscles  on  the  right  side  of  the  head 
or  in  the  muscles  moving  the  eyeballs  to  the  right.  As  a  re- 
sult the  head  still  fell  toward  the  left,  and  no  after-nystag- 
mus developed.  The  absence  of  nystagmus  during  the 
last  cold  irrigation  seemed  due  to  the  fact  that  compensa- 
tory adjustment  for  the  disturl^ed  labyrinthine  relations 
had  already  been  made  through  ocular  impressions,  aided 
by  voluntary  effort.  Moreover,  the  condition  of  the  recep- 
tors in  the  left  labyrinth,  after  so  many  cold  irrigations, 


PHYSIOLOGY  279 

was  such  that  effects  from  further  cold  irrigations  were 
temporarily  absent. 

With  the  subject  lying  supine  in  the  swing  and  rest- 
ing, the  pulse-rate  and  blood-pressure  were  48  and  125. 
During  bilateral  irrigation  at  50°  F.  there  was  no  nystag- 
mus or  discomfort,  whilst  the  pulse-rate  and  blood-press- 
ure were  48  and  185.  Immediately  after  the  irrigation  a 
brisk  rotation  was  given  in  the  coronal  plane  and  with  the 
watch.  On  suddenly  checking  the  swing  the  usual  after- 
nystagmus  was  present,  i.e.,  rotary  against  the  watch  with 
external  objects  appearing  to  move  about  the  subject's 
body,  i.e.,  upon  the  left,  over  the  head  and  down  the  right 
side.  The  nystagmus  lasted  only  a  moment  or  two. 
From  this  it  seems  that  bilateral  cold  irrigations  do  not 
completely  abolish  the  function  of  the  ampullary  receptors 
in  the  superior  canals. 

After  bilateral  irrigation  at  50°  F.  rotation  in  the  sag- 
ittal plane  "occiput  first"  caused  vertical  after-nystagmus 
toward  the  feet  and  with  a  slight  lateral  tendency  toward 
the  right.  During  the  swing  visual  fixation  was  impos- 
sible and  the  subject  was  made  very  dizzy. 

Rotation  in  the  sagittal  plane  ' '  face  first, ' '  given  after 
bilateral  irrigation  at  50°  F. ,  caused  vertical  after-nystag- 
mus with  up  and  down  movements  of  the  eyes.  The 
direction  of  the  movements  was  slanting  from  the  left  side 
of  the  head  toward  the  right  foot.  External  objects  seemed 
to  move  "up  and  down"  in  the  same  direction.  The  ab- 
rupt stopping  of  this  last  rotation  made  the  subject  very 
sick.  This  result,  unusual  for  such  rotations,  is  to  be  at- 
tributed to  the  relatively  enhanced  irritability  of  the  am- 
pullary receptors  of  the  posterior  canals  caused  by  the  de- 
pression of  the  ampullary  receptors  of  the  superior  canals 
following  the  irrigation.  The  irrigations  given  in  these 
experiments  all  lasted  not  less  than  3,  nor  more  than 
4  minutes. 

The  effect  of  galvanism  upon  the  semicircular  canals 
resolves  itself  also  into  one  of  exaltation  or  depression  of 
the  ampullary  receptors.  The  well-known  phenomena  of 
electrotonus,  coupled  with  the  foregoing  observations,  af- 
ford an  easy  explanation.  Thus,  with  the  cathode  over  the 
left  mastoid  area  the  adjacent  ampullary  nerye  elements  are. 


280  SEMICIRCULAR  CANALS 

put  in  the  state  of  katelectrotonus,  i.e.,  their  irritability 
is  increased  as  in  the  case  of  hot  irrigations  in  the  left  ear, 
and  there  is  lateral  inclination  of  the  head  toward  the 
right  with  horizontal  nystagmus  toward  the  left.  With 
the  anode  over  the  left  mastoid  area,  the  adjacent  ampul- 
lary  nerve  elements  are  put  in  a  state  of  anelectrotonus, 
i.e.,  of  decreased  irritability  with  resulting  phenomena 
similar  to  those  of  cold  irrigations  in  the  left  ear.^*^ 
With  the  cathode  over  one  mastoid  area,  and  the  anode 
over  the  other,  the  maximum  effect  is  produced  as  when 
a  cold  irrigation  is  given  in  one  ear  and  a  hot  irrigation 
in  the  other  simultaneously. 

From  the  definite  direction  of  the  movements  that 
occur  in  response  to  rotations,  aural  irrigations  and  gal- 
vanism, it  is  manifest  that  the  receptors  of  each  semicir- 
cular canal  and  vestibule  are  functionally  related  to 
definite  groups  of  muscles.  Thus  in  hot  irrigations  of 
the  left  ear,  the  head  is  actively  drawn  toward  the  right 
shoulder,  and  since  this  is  the  result  of  temporarily  in- 
creased irritability  (lowered  threshold  value)  of  the  am- 
pullary  receptors  in  the  left  horizontal  canal,  it  is  evident 
that  these  receptors  and  their  associated  arcs  are  in  rela- 
tion with  the  muscles  on  the  right  side  of  the  head  and 
neck  which  govern  such  a  movement.  Similarly,  in  cold 
irrigations  of  the  left  ear  by  depression  of  the  ampullary 
receptors  of  the  left  horizontal  canal  and  consequent 
diminished  tonus  in  the  muscles  functionally  connected 
with  them,  viz. :  those  of  the  opposite  side  of  the  neck  and 
head,  there  is  deviation  of  the  head  toward  the  left.  Thus 
it  is  manifest  that  a  crossed  relation  exists  between  the 
horizontal  canal  on  one  side  of  the  body  and  the  muscles 
with  which  it  is  functionally  associated  upon  the  other 
side.  When  the  muscular  associations  of  the  ampullary 
receptors  of  the  superior  and  posterior  canals  are  consid- 
ered, the  evidence  points  to  the  fact  that  each  pair  of 
canals  acts  as  the  antagonist  of  the  other  pair  when  both 
members  of  one  or  other  of  the  pairs  are  equally  and  simul- 
taneously stimulated  or  depressed,  as  in  the  case  of  bilateral 
hot  or  cold  irrigations,  or  in  rotations  in  the  sagittal 
plane.  The  evidence  obtained  from  various  sources  points 
to  the  fact  that  the  receptors  of  the  superior  canals  are 
associated  functionally  with  the  muscles  of  the  head  and 


PHYSIOLOGY  281 

neck,  situated  dorsally,  which  tend  to  draw  the  head  back- 
ward. The  evidence  of  this  relation  is  supplied  in  part 
by  the  phenomena  manifested  during  bilateral  cold  irriga- 
tions where  the  head  falls  forward  from  depreciation  of 
the  normal  reflex  tonus  in  the  muscles  referred  to. 
Furthermore  the  receptors  of  each  superior  canal  seem  to 
be  in  relation  with  the  muscles  of  the  head  and  neck  of 
the  opposite  side  and  situated  dorsally,  i.e.,  they  are  in 
crossed  relation  with  one-half  of  the  muscles  just  men- 
tioned as  tending  to  draw  the  head,  when  bent  forward, 
back  into  the  vertical  position.  This  conclusion  is  based 
upon  the  fact  that  in  single  cold  irrigations,  say  of  the 
left  auditory  canal,  the  head  inclines  not  only  to  the  left, 
but  rotates  somewhat  on  the  long  axis  of  the  body,  so  that 
the  chin  points  toward  the  right.  Similarly  it  may  be 
deduced  that  the  posterior  canals  are  associated  function- 
ally with  the  muscles  of  the  neck  which  tend  to  draw  the 
head  forward.  This  rough  general  outline  of  the  muscular 
associations  of  the  ampullary  receptors,  based  on  clinical 
studies,  is  in  harmony  with  the  phenomena  that  follow 
section  of  the  canals  in  animals. 

There  are  thus  efficient  balanced  mechanisms  constantly 
in  action,  whereby  every  displacement  of  the  head  is  com- 
pensated or  corrected  in  a  reflex  manner.  The  influence 
of  the  otoliths  is  intentionally  omitted  to  avoid  confusion. 
Normally,  therefore,  equilibrium  is  maintained  reflexly, 
each  displacement  being  met  by  active  stimulation  (en- 
hanced tonus)  of  the  muscles  tending  to  correct  such  dis- 
placement or  by  inhibition  (diminished  tonus)  of  those 
muscles  that  tend  to  produce  it. 

In  studying  the  muscles  involved  in  the  mechanism  of 
nystagmus  caused  by  rotation,  aural  irrigations,  or  galvan- 
ism, one  is  struck  at  once  by  tho  similarity  of  their  be- 
haviour to  that  of  the  muscles  that  control  the  displace- 
ments of  the  head.  Thus  in  displacements  of  the  head  in 
aural  irrigations,  the  muscles  upon  the  side  toward  which 
the  displacement  takes  place  are  in  an  absolutely  or  rela- 
tively heightened  state  of  tonus  whilst  their  opponents  of 
the  opposite  side  are  in  a  state  of  diminished  tonus. 
Similarly  the  muscles  that  tend  to  turn  eyeballs  in  one 
direction  or  the  other  are  for  the  moment  in  a  heightened 
state  of  tonus,   whilst  the  tonus    of    their  opponents  is 


282  SEMICIRCULAR   CANALS 

momentarily  depressed.  This  rule  applies  to  the  rotary 
and  vertical  as  well  as  to  the  horizontal  movements  of  the 
eyes.  The  grouping  of  the  opponent  muscles  in  nystag- 
mus corroborates  what  has  been  stated  concerning  the 
grouping  of  the  muscles  controlling  displacements  of  the 
head.  Thus  the  external  rectus  of  one  eye  works  in  con- 
junction with  the  internal  rectus  of  the  other  eye,  both  f 
being  in  turn  opposed  by  the  analogous  muscles  on  the 
opposite  side  of  each  eyeball.  In  vertical  nystagmus 
both  inferior  recti  are  the  opponents  of  both  superior 
recti.  In  rotary  nystagmus  the  superior  oblique  of  the 
right  eye,  and  the  inferior  oblique  of  the  left,  act  in  con- 
junction, their  opponents  being  the  inferior  oblique  of  the 
right  and  superior  oblique  of  the  left  eye  respectively. 
In  nystagmus,  the  long  steady  pull  of  the  eyes  indicates 
in  a  general  way  that  the  muscles  responsible  for  it  are  in 
a  state  of  heightened  tonus  (absolute  or  relative) ,  whilst 
the  short  jerky  movements  that  give  direction  to  the  nys- 
tagmus indicate  in  general  a  lessened  tonus  or  rhythmic 
inhibition  in  the  related  muscles.  Thus  in  cold  irriga- 
tions of  the  left  ear  with  displacement  of  the  head  toward 
the  left,  and  horizontal  nystagmus  toward  the  right,  the 
steady  pull  of  the  eyeballs  to  the  left  indicates  that  the 
muscles  responsible  for  it  are  in  a  relatively  heightened 
state  of  tonus,  and  are  consequently  in  functional  relation 
with  the  ampullary  receptors  of  the  right  horizontal  canal 
which  are  relatively  exalted  as  to  their  sensibility  (low- 
ered threshold  value) ,  whilst  their  oj)ponents  are  in  rela- 
tion with  the  ampullary  receptors  of  the  left  horizontal 
canal  which  are  absolutely  depressed  by  the  action  of  the 
cold  irrigation.  The  tonus  in  the  muscles  associated  with 
either  set  of  movements  is  not  constant,  but  is  subject  to 
alternating  changes  effected  by  means  of  reciprocal  in- 
nervation. 

Again,  in  rotations  in  the  mesial  plane,  let  us  say 
"occiput  first, "  the  primary  nystagmus  is  directed  toward 
the  vertex  capitis,  with  the  slow  and  steady  movement, 
during  which  vision  is  possible,  directed  toward  the  feet, 
The  latter  movement  shows  tlmt  the  apparatus  responsible 
for  it  is  in  a  heightened  state  of  tonus  corresponding  with 
the  enhanced  irritability  of  the  ampullary  receptors  of 
both  posterior  canals.    Similarly,  in  rotations  in  the  mesial 


PHYSIOLOGY 


283 


plane,  ''face  first,"  the  steady  pull  of  the  primary  nys- 
tagmus is  toward  the  vertex  corresponding  with  the 
heightened  irritability  of  the  ampullary  receptors  in  both 
superior  canals. 

In  rotary  nystagmus  the  superior  ol^lique  acts  under 
the  influence  of  the  ampullary  receptors  of  the  superior 
canal  of  the  same  side,  and  perhaps  of  the  posterior  canal 
of  the  opposite  side.     Owing  to  the  decussation  of  the^ 


Diagram  illustrating  the  relations  of  the  semicircular  canals  to 
the  oculo-motor  nuclei.  A,  the  right  horizontal  canal ;  B, 
the  right  superior  canal ;  C,  the  right  posterior  canal.  The 
Roman  numerals  indicate  the  oculo-motor  nuclei.  The  ar- 
rows indicate  the  direction  in  which  the  tendency  of  the  cur- 
rent of  endolymph  begets  the  stronger,  irritative  reaction. 


fourth  nerve  the  relation  between  the  superior  and  pos- 
terior canals  and  the  superior  oblique  muscle  is  an  un- 
crossed one.  See  diagram.  A  glance  at  a  good  specimen 
of  the  bony  canals  exposed  in  situ,  with  the  relations  to. 
the  various  parts  and  planes  of  the  skull  preser^^ed,  will 
at  once  convince  one  that  rotation  in  the  coronal  plane; 


284  SEMICIRCULAR   CANALS 

against  the  watch  tends  to  displace  the  endolymph  in  the 
right  superior  canal  from  the  ampulla  toward  the  canal. 

Similarly,  the  position  and  direction  of  the  superior 
canals  is  such  that  the  endolymph  in  them  is  liable  to  be 
influenced  by  aural  irrigations,  but  not  by  rotations 
strictly  confined  to  a  plane  perpendicular  to  the  long  axis. 
In  rotations  in  the  coronal  plane  with  the  watch,  there  is 
a  tendency  to  displacement  of  the  endolymph  away  from 
the  ampulla  in  the  left  superior  canal.  The  ampullary 
receptors  of  the  left  superior  canal  are  thus  actively  stimu- 
lated, thereby  enhancing  the  tonus  of  the  related  muscles, 
viz. ,  the  inferior  oblique  on  the  right,  and  the  superior 
oblique  on  the  left  side,  which  initiates  rotary  nystagmus 
with  the  watch. 

In  unilateral  cold  irrigations  the  posterior  canal  is  not 
affected,  unless  perhaps  the  irrigation  is  very  prolonged, 
and  then  the  effect  is  to  reinforce  that  of  the  superior 
canal  of  the  opposite  side,  since  these  canals  stand  in  the 
relation  of  antagonists  probably. 

Summary  of  the  Relations  of  the  Ocular  Muscles. 

1.  The  external  rectus  is  mainly  in  relation  with  the 
ampullary  receptors  of  the  horizontal  semicircular  canal 
of  the  opposite  side. 

2.  The  superior  oblique  is  mainly  in  relation  with  the 
ampullary  receptors  of  the  superior  and  possibly  witk 
those  of  the  inferior  canal  of  the  same  side. 

3.  The  internal  rectus  is  mainly  in  relation  with  the 
ampullary  receptors  of  the  horizontal  canal  of  the  same 
side,  though  the  part  of  the  third  nerve  nucleus  governing 
its  associated  movement  with  the  external  rectus  may,  on 
account  of  the  partial  decussation  within  the  nucleus  be 
in  relation  with  the  horizontal  canal  of  the  opposite  side, 
i.e.,  the  muscle  and  the  origin  of  its  motor  neurones  are 
on  opposite  sides  of  the  median  line. 

4.  The  inferior  o})lique  is  mainly  in  relation  with  the 
ampullary  receptors  of  the  superior  and  posterior  canals 
of  the  opposite  side. 

5.  The  superior  and  inferior  recti,  as  well  as  the  leva- 
tores  palpebrarum  and  part  of  the  orbiculares  palpebrarum, 
act  synchronously  on  both  sides  of    the  body,  and  are 


PHYSIOLOGY  285 

therefore  in  relation  with  the  receptors  of  the  semicircular 
canals  of  both  sides,  the  superior  recti  and  the  levatores 
palpebrarum  being  in  relation  with  the  superior  semicir- 
cular canals,  whilst  the  inferior  recti  and  the  orbiculares 
are  in  relation  with  the  posterior  canals.  The  relations 
between  the  nuclei  of  the  III,  VII,  and  XII  nerves  have 
already  been  discussed.  These  bilateral  connections  are 
affected  through  the  median  portion  of  the  third  nerve 
nucleus  or  through  the  partial  decussation  that  occurs 
within  the  nucleus,  since  some  anatomists  (Tsuchida^*) 
have  recently  denied  the  existence  of  a  well-marked  un- 
paired central  nucleus  as  described  by  Perlia  and  appar- 
ently sustained  by  the  observations  of  Starr  and  those  of 
Kahler  and  Pick.^^^ 

It  should  be  noted  that  the  superior  oblique  of  one  eye 
is  associated  with  the  inferior  oblique  of  the  opposite  eye 
in  the  mechanism  of  rotary  nystagmus. 

The  associations  of  the  ocular  muscles  above  enumer- 
ated are  based  on  numerous  observations  of  the  nystagmic 
movements  that  accompany  rotations,  aural  irrigations 
and  galvanism.  In  the  light  of  these  associations  the 
phenomena  that  follow  section  of  the  vestibular  nerve,  in 
the  sheep  for  instance,  as  done  by  Biehl,^^  are  readily  ex- 
plained. Thus,  in  section  of  the  right  vestibular  nerve 
the  right  eye  was  turned  downward  and  outward,  whilst 
the  left  was  turned  upward  and  inward.  Here  the  internal 
rectus  in  the  right  and  the  external  rectus  in  the  left  eye 
were  severed  from  their  labyrinthine  receptors  through 
which  they  derived  their  reflex  tonus,  thus  relatively  en- 
hancing the  tonus  of  their  opponents  with  a  tendency  of 
the  eyes  to  deviate  in  general  toward  the  right.  Again 
the  right  superior  oblique  and  left  inferior  oblique  are 
severed  from  their  labyrinthine  receptors  with  consequent 
loss  of  reflex  tonus  which  relatively  enhances  the  tonus 
of  their  opponents  with  a  tendency  of  the  right  eye  to  be 
drawn  downward  as  a  whole,  by  the  right  inferior  oblique 
and  a  tendency  of  the  left  eye  to  be  drawn  upward  as  a 
whole  by  the  unopposed  action  of  the  left  superior 
oblique.  The  superior  and  inferior  recti,  as  well  as  the 
levatores  and  orbiculares  palpebrarum,  are  so  affected  that 
no  deviation  results  owing  to  the  fact  that  antagonistic 
muscles  are  equally  affected,  and  that  these  muscles  are 


286  SEMICIRCULAR   CANALS 

in  free  relation  with  the  semicircular  canals  of  both  sides. 
Peculiarities  in  regard  to  the  site  of  insertion  of  the  ocular 
muscles,  and  more  especially  of  the  oblique  muscles  and 
difficulty  in  appreciating  the  net  mechanical  result  of  the 
working  action  of  the  ocular  muscles,  as  a  whole,  have  been 
the  cause  of  much  discrepancy  in  the  nystagmus  and  de- 
viations observed  after  section  of  the  VIII  nerve  and  in 
other  experiments  upon  the  labyrinth  and  cerebellum. 

Attempts  to  study  the  deviation  of  the  eyes  under 
direct  irritation  of  each  separate  canal  were  made  by  De 
Cyon,  ^^  Hogj^es,  ^^^  Lee  ^^^  and  others,  but  owing  to  the 
twofold  element  of  the  nystagmus,  coupled,  in  some  in- 
stances, with  the  difficulty  of  confining  the  effects  of  irri- 
tation to  one  canal,  the  results  were  conflicting.  More- 
over, the  labyrinthine  receptors  are  exceedingly  sensitive 
to  thermic  and  other  forms  of  stimuli,  responding  even 
to  light  (Schwartze^^^).  De  Cyon  himself  revised  and 
corrected  his  first  findings,  but  his  later  findings,  accord- 
ing to  Ferrier,^  were  even  more  unsatisfactory  than  his 
first  ones. 

We  have  seen  that  whatever  tends  to  produce  a  current 
of  endolymph  toward  the  ampulla  of  the  horizontal  canal 
and  away  from  the  ampullae  of  the  posterior  and  superior 
canals,  causes  characteristic  primary  phenomena  by  way 
of  displacement  of  'jhe  head  in  a  certain  direction  with  nys- 
tagmus of  a  certain  type  and  direction,  whilst  in  the  ex- 
periments of  Ewald,  '^  secondary  phenomena  of  retardation 
accompanied  manipulations  tending  to  drive  the  endo- 
lymph in  the  reverse  direction.  With  due  credit  to  Lee,  ^^^ 
who  showed  that  the  compensatory  movements  occurring 
in  fishes  subjected  to  rotation  exactly  correspond  with 
those  caused  by  direct  irritation  of  the  canals,  the  results 
of  experiments  such  as  those  done  by  Hogyes  on  animals, 
and  repeated  by  surgeons  on  the  human  subject  are  always 
open  to  suspicion,  for  touching  the  horizontal  membra- 
nous canals  may  give  directly  opposite  results,  depending 
on  the  direction  in  which  th6  endolymph  is  forced.  Ex- 
periments like  these  are  the  chief  cause  of  the  intermina- 
ble discussions  upon  the  symptomatology  of  labyrinthine 
disease  as  to  whether  the  phenomena  are  due  to  irritation 
or  destruction.  The  only  rational  way  to  analyze  such 
symptoms  is  to  consider  them  with  reference  to  enhanced 


PHYSIOLOGY  287 

or  depressed  irritability  (absolute  or  relative)  of  the  laby- 
rinthine receptors  on  either  side  of  the  body  and  in  each 
of  the  three  semicircular  canals.  With  such  characteristic 
and  definite  phenomena  as  the  normal  reactions  afford, 
little  difficulty  should  be  experienced  in  the  interpretation 
of  labyrinthine  reactions  in  diseased  conditions. 


CHAPTER  XX 

MECHANISM   OF  THE  NYSTAGMUS   OF   ROTATIONS, 
AURAL   IRRIGATIONS   AND   GALVANISM 

The  crossed  relations  of  the  semicircular  canals  to  the 
ocular  muscles  (excepting  the  superior  oblique)  and  to  the 
muscles  that  control  the  movements  of  the  head  have  been 
fully  discussed.  It  remains  to  consider  the  relations  of 
the  nuclei  of  the  nerves  supplying  these  muscles  with 
motor  influence.  For  the  sake  of  simplicity  the  ocular 
muscles  alone  shall  be  discussed  in  this  respect,  but  the 
deductions  will  apply  equally  to  all  other  muscles  that 
receive  tonus  through  afferent  labyrinthine  impulses. 
Since  Duval  and  Laborde'"^^  found  that  irritation  of  the 
sixth  nucleus  caused  conjugate  deviation  of  the  eyes  toward 
the  side  of  stimulation,  it  was  believed  that  the  sixth 
nucleus  co-ordinated  and  controlled  the  action  of  the  ex- 
ternal rectus  of  the  same  side  and  of  the  internal  rectus  of 
the  opposite  side.  This  necessitated  a  connecting  link 
between  the  sixth  nucleus  of  one  side  and  that  part  of  the 
third  nucleus  controlling  the  action  of  the  internal  rectus 
of  the  opposite  side.  The  posterior  longitudinal  fasciculus 
afforded  an  easy  way  of  communication,  and  it  was  as- 
sumed that  fibres  passed  from  the  sixth  nucleus  by  way  of 
the  posterior  longitudinal  fasciculus  to  the  nucleus  of  the 
third  nerve  of  the  opposite  side.  Schafer,  "  however, 
denies  that  any  fibres  pass  from  the  VI  or  III  nucleus  to 
the  posterior  longitudinal  fasciculus.  A  little  considera- 
tion suffices  to  convince  one  that  if  the  sixth  nucleus  con- 
trols the  conjugate  deviation  of  the  eyes,  some  other  nu- 
cleus must  control  the  combined  action  of  the  muscles  that 
cause  the  characteristic  displacement  of  the  head  which 
accompanies  the  conjugate  deviation  of  the  eyes.  Still 
further  consideration  will  convince  that  yet  another  centre 
must  be  assumed  to  control  the  movements  of  the  head 
and  eyes  so  that  they  shall  act  in  harmony.     Without 

288 


PHYSIOLOGY  289 

further  discussion  it  may  be  stated  that  whilst  minor  cen- 
tres and  groups  of  centres  in  the  cord  or  elsewhere  have 
certain  co-ordinating  powers  of  an  order  adapted  to  certain 
needs  and  uses,  the  higher  and  more  complex  adjustments 
are  not  secured  by  individual  lower  motor  centres,  but 
these  latter  act  in  obedience  to  higher  co-ordinating  cen- 
tres variously  situated,  but  chiefly,  though  not  exclusively, 
in  the  cerebellum.  In  seeking  the  nervous  mechanism  of 
nystagmus,  therefore,  we  are  at  once  directed  not  to  the 
vestibular  nucleus  of  reception  or  any  single  motor  nucleus 
in  the  medulla  or  elsewhere,  but  to  the  cerebellum.  The 
work  of  Ferrier,  ^  too  much  neglected  by  those  who  have 
made  studies  of  the  semicircular  canals,  throws  much 
light  upon  this  i^hase  of  the  subject.  Ferrier  studied  the 
deviations  of  the  eyes  in  the  monkey  and  found  as  follows : 

1.  Electrical  stimulation  of  the  anterior  portion  of  the 
middle  lobe  of  the  cerebellum  caused  the  animal  to  throw 
the  head  backward.  This  was  accompanied  by  an  upward 
deviation  of  the  eyeballs  toward  the  vertex. 

2.  Electrical  stimulation  of  the  posterior  portion  or 
declivity  of  the  upper  vermis  caused  the  head  to  be  dis- 
placed forward  and  downward  toward  tte  chest,  which  was 
associated  with  a  deviation  of  the  eyes  downward.  Stim- 
ulation of  the  cerebellum  caused  contraction  of  the  pupils, 
especially  marked  upon  the  side  of  stimulation. 

3.  Irritation  of  the  posterior  superior  lobes  upon  the 
left  of  the  median  line  caused  displacement  of  the  head 
upward  and  to  the  left,  both  eyes  turning  upward  and  to 
the  left. 

4.  Irritation  of  the  posterior  superior  lobes  upon  the 
right  of  the  median  line  caused  upward  displacement  of 
the  head  toward  the  right,  with  a  corresponding  displace- 
ment of  the  eyes  upward  and  to  the  right. 

5.  Irritation  to  the  left  or  right  of  the  pyramid  of  the 
middle  lobe  (pyramis  vermis)  caused  both  eyes  to  deviate 
to  the  left  or  right  respectively. 

6.  Irritation  of  the  posterior  extremity  of  the  upper 
vermiform  process  (declive  monticuli)  caused  both  eyes 
to  deviate  straight  downward  with  the  electrodes  upon  the 
middle  of  this  process.  With  the  electrodes  to  the  left  or 
right  of  this  process  the  eyes  deviated  downward  and  to 
the  left  and  right  respectively. 


DIAGRAMS  ILLUSTRATING  REACTIONS  OBTAINED 
BY  FERRIER  UPON  STIMULATION  OF  VARIOUS 
PARTS   OF   THE   CEREBELLUM. 

IN   THE   MONKEY 

1.  Anterior  portion  of  the  middle  lobe. 

2.  Posterior  portion  or  declivity  of  the  upper 

vermis. 

3.  Posterior  superior  loJDes  to  left  of  midline. 

4.  Posterior  superior  lobes  to  right  of  midline. 

5.  Pyramid  of  middle  lobe  (pyramis  vermis)  to 

left  of  midline. 

6.  Pyramid  of  middle  lobe  (pyramis  vermis)  to 

right  of  midline. 

7.  Posterior  extremity    of    upper    vermiform 

process  (declive  monticuli). 

8.  Posterior    extremity    of    upper    vermiform 

process  to  left  of  process. 

9.  Posterior   extremity    of    upper    vermiform 

process  to  right  of  process. 

10.  Upper  vermiform  process  at  its  anterior  ex- 

tremity in  midline. 

11.  Upper  vermiform  process  at  its  anterior  ex- 

tremity to  left  of  midline. 

12.  Upper   vermiform   process    at   its    anterior 

extremity  to  right  of  midline. 

13.  Lateral  lobe  (semilunar  lobule)  on  the  left. 

14.  Lateral  lobe  on  the  right. 

15.  Flocculus. 

IN    RABBITS 

1.  Upper  and  back  portion  of  middle  lobe. 

2.  Middle  and  lower  portion  of  middle  lobe. 

3.  Left  lateral  lobe,  upper  lobule. 

4.  Left  lateral  lobe,  middle  lobule. 

5.  Left  lateral  lobe,  lower  lobule. 

6.  Left  lateral  lobe,  anterior  lobule. 

7.  Anterior  portion  of  cerebellum. 

290 


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PHYSIOLOGY  291 


IN    DOGS 


1.  Pyramid,  to  the  left  of  it. 

2.  Pyramid,  to  the  right  of  it. 

3.  Upper  vermiform  process,  posterior  end  of 

declive  in  midline. 

4.  Upper  vermiform  process,  posterior  end  of 

declive  on  left  of  midline. 

5.  Upper  vermiform  process,  posterior   end  of 

declive  on  right  of  midline. 

6.  Lateral  lobe,  posterior  superior  lobe  on  right 

side. 

7.  Flocculus  region. 


IN    CATS 

1.  Median  lobe,  right  curve. 

2.  Median  lobe,  left  curve. 

3.  Upper  vermiform  process,  posterior  end  of 

declive  in  midline. 

4.  Upper   vermiform  process,  posterior  end  of 

declive  to  left  of  midline. 

5.  Upper  vermiform  process,  posterior  end  of 

declive  to  right  of  midline. 

6.  Lateral  lobe,  posterior  superior  lobule  on  the 

left. 

7.  Lateral  lobe,  posterior  superior  lobule  on  the 

right. 


Section  of  the   right  vestibular  nerve  in  the  ^i      ^\ 
sheep  (Biehl).  V      ^ 


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292  SEMICIRCULAR   CANALS 

7.  Irritation  of  the  upper  vermiform  process  at  its 
anterior  extremity  (monticiiliis  cerebelli)  (a)  in  the  mid- 
dle line  caused  both  eyes  to  deviate  directly  upward;  (b) 
on  the  left  by  the  median  line  caused  both  eyes  to  deviate 
diagonally  upward  and  to  the  left  without  rotation;  (c)  to 
the  right  of  the  median  line  caused  both  eyes  to  deviate 
upward  and  to  the  right. 

8.  Irritation  of  the  lateral  lobe  (semilunar  lobule)  (a) 
upon  the  left  caused  both  eyes  to  deviate  upward  and  to 
rotate  to  the  left  (with  the  watch) ;  (b)  upon  the  right 
caused  both  eyes  to  deviate  upward  and  to  rotate  toward 
the  right  (against  the  watch) . 

9.  Irritation  of  the  flocculus  caused  both  eyes  to 
rotate  upon  their  antero-posterior  axes. 

Experimenting  with  rabbits,  Ferrier  found : 

1.  Irritation  of  the  upper  and  back  portion  of  the 
middle  lobe  of  the  cerebellum  caused  horizontal  deviation 
of  the  eyes  to  the  right,  whilst  irritation  of  the  middle 
and  lower  part  caused  deviation  of  the  eyes  to  the  left. 
I  2.  In  the  left  lateral  lobe  irritation  (a)  of  the  upper 
lobule  caused  deviation  of  the  left  eye  upward,  with  inward 
rotation,  i.e.,  against  the  watch,  and  downward  deviation 
of  the  right  eye  with  outward  rotation  (i.e.,  against  the 
watch) ;  (b)  of  the  middle  lobule  caused  upward  deviation 
of  the  left  eye  with  outward  rotation  (with  the  watch) ,  and 
downward  deviation  of  the  right  eye  with  inward  rotation 
(with  the  watch) ;  (c)  of  the  lower  lobule  caused  both 
eyes  to  rotate  to  the  right  (i.e.,  against  the  watch)  upon 
the  antero-posterior  axes;  (d)  of  the  anterior  lobule 
caused  rotation  of  both  eyes  upon  the  antero-posterior  axes 
toward  the  left  (i.e.,  with  the  watch). 

3.  Irritation  of  the  anterior  part  of  the  cerebellum 
caused  both  eyes  to  deviate  upward,  followed  by  vertical 
nystagmus. 

In  these  experiments  Ferrier  also  noted  protrusion  of 
the  eyeballs,  increased  convexity  of  the  cornea,  dilatation 
of  the  nostrils,  movements  of  the  limbs  upon  the  side  of 
irritation,  and  twitching  of  the  ears. 

In  dogs  Ferrier  found: 

1.  Irritation  to  the  left  or  right  of  the  pyramid  caused 
deviation  of  the  eyes  to  the  left  and  right  respectively. 

2.  Irritation  of  the  upper  vermiform  process,  posterior 


PHYSIOLOGY  29B 

extremity  of  the  declive:  (a)  in  the  middle  line  caused 
both  eyes  to  deviate  downward;  (b)  on  the  left  of  the 
middle  line  caused  both  eyes  to  deviate  dowTiward  and  to 
the  left;  (c)  on  the  right  of  the  median  line  caused  both 
eyes  to  deviate  downward  and  to  the  right. 

3.  Irritation  of  the  lateral  lobe,  posterior  superior  lobe, 
on  the  right  side  caused  both  eyes  to  deviate  upward  and 
to  the  right,  with  rotation  upon  their  antero-posterior  axes 
to  the  right  (against  the  watch) . 

4.  Irritation  of  the  flocculus  region  caused  rotation  of 
both  eyes  on  the  antero-posterior  axes,  sometimes  to  the 
right  and  sometimes  to  the  left  (i.e.,  against  and  with 
the  watch) . 

In  cats  Ferrier  found : 

1.  Irritation  of  the  median  lobe:  (a)  right  curve, 
caused  horizontal  deviation  to  the  right;  (b)  left  curve, 
caused  horizontal  deviation  to  the  left. 

2.  Irritation  of  the  upper  vermiform  process — posterior 
extremity  of  the  declive:  (a)  in  the  middle  caused  both 
eyes  to  deviate  dow^nward;  (b)  to  the  left  caused  both  eyes 
to  deviate  downward  and  to  the  left;  (e)  to  the  right 
caused  deviation  of  both  eyes  downward  and  to  the  right. 

3.  Irritation  of  the  lateral  lobe — postero-superior  lobule 
at  various  points :  (a)  on  the  left  caused  deviation  of  both 
eyes  upward  and  to  the  left ;  (b)  on  the  right  caused  devi- 
ation of  both  eyes  upward  and  to  the  right. 

In  addition  to  the  foregoing,  irritation  of  the  left  side 
of  the  cerebellum  caused  the  left  pupil  to  contract,  and 
threw  the  left  limbs  into  action. 

In  pigeons  Ferrier  found  no  especial  movements  of  the 
eyes  upon  irritation  of  the  cerebellum,  but  irritation  of 
the  right  or  left  side  of  the  cerebellum  caused  the  head  to 
be  jerked  back  and  toward  the  side  stimulated,  and  fre- 
quently the  leg  of  the  same  side  was  brought  up  and  the 
wing  flapped. 

With  such  an  array  of  facts  from  so  reliable  an  ob- 
server, the  co-ordinating  power  attributed  to  the  sixth 
nucleus  lapses  into  insignificance,  and  it  becomes  at  once 
apparent  that  the  connections  between  the  semicircular 
canals  on  the  one  hand,  and  the  motor  nuclei  of  the  ocular 
and  other  muscles  are  mainly  indirect  and  effected  by 
paths  that  traverse  the  various  portions  of  the  cerebellum. 


294  SEMICIRCULAR  CANALS 

And  since  each  half  of  the  cerebellum  is  mainly  related  to 
the  musculature  of  the  homolateral  side,  whilst  the  semi- 
circular canals,  as  has  been  already  shown,  are  related 
chiefly  to  the  musculature  of  the  contralateral  side,  it 
follows  that  the  connection  between  the  semicircular  canals 
and  the  cerebellum  is  functionally  in  the  main  a  crossed 
one.  That  it  is  mainly  so  anatomically,  may  be  gathered 
from  a  glance  at  the  relations  of  the  various  labyrinthine 
and  other  fibre  paths  roughly  indicated  in  previous  chap- 
ters. The  labyrinthine  balanced  mechanisms  which  have 
been  shown  to  exist,  act  chiefly  through  the  medium  of 
the  cerebellum  and  the  nystagmus,  and  disturbances  of 
equilibrium  consequent  upon  rotations,  aural  irrigations 
and  galvanism  are  produced  by  enhancement  or  inhibition 
(depression)  of  one  or  other  of  the  elements  of  these  bal- 
anced mechanisms.  Thus  horizontal  nystagmus  to  the 
right  in  cold  aural  irrigation  of  the  left  ear  is  caused  by 
depression  or  increased  threshold  value  in  the  ampullary 
receptors  of  the  left  horizontal  canal  which  causes  a  rela- 
tive enhancement  or  lowered  threshold  value  in  the  anta- 
gonistic ampullary  receptors  of  the  right  horizontal  canal, 
whereby  the  normal  afferent  tonus  impulses  of  the  latter 
acquire  an  abnormal  relative  value  which  is  tantamount 
to  stimulation  of  that  portion  of  the  cerebellum  on  the 
opposite  (left)  side  which  receives  them.  This  causes  a 
steady  deviation  of  the  eyes  to  the  left  in  the  horizontal 
plane  as  in  irritation  to  the  left  of  the  pyramid  of  the 
middle  lobe  of  the  cerebellum  by  Ferrier.  When,  how- 
ever, the  eyeballs  have  reached  a  certain  degree  of  devia- 
tion to  the  left,  the  muscles  causing  the  deviation  relax, 
giving  way  to  the  action  of  their  antagonists.  These 
latter  by  a  series  of  rapid  clonic  contractions  pull  the  eyes 
in  jerks  from  left  to  right  for  a  certain  distance  when  the 
eyes  once  more  begin  moving  toward  the  left  under  tonic 
well  co-ordinated  contractions  of  the  governing  muscles. 
During  the  steady  deviation  of  the  eyes  to  the  left,  exe- 
cuted by  the  left  external  rectus  and  the  right  internal 
rectus  acting  conjointly,  the  opponents  of  these  muscles 
are  in  a  state  of  inhibition  (reciprocal  innervation),  such 
as  Sherrington  212  has  demonstrated  for  ocular  movements 
originating  in  the  cerebral  cortex.  In  Sherrington's  ex- 
periments the  inhibition  was  dependent  upon  lower  cen- 


PHYSIOLOGY  295 

i 

tres  since  it  could  be  elicited  after  removal  of  the  frontal 
and  occipital  areas.  Sherrington  *^  showed  that  inhibition 
is  '  'part  and  parcel' '  of  the  reflex  action.  The  site  of  inhi- 
bition in  the  simple  spinal  reflex  is  central,  that  is,  some- 
where in  the  grey  matter,  probably  at  the  ultimate  synapse 
between  the  afferent  and  efferent  (motor)  neurones.  In 
reactions  from  irritation  of  the  motor  cortex  the  seat  of 
inhibition  lies  probably  at  their  confluence  upon  the  motor 
neurone,  i.e.,  at  the.  ultimate  synapse.  It  is  likely,  how- 
ever, that  in  other  fields  of  action  one  cortical  element 
inhibits  another  (Sherrington^^).  In  the  reflex  compen- 
sations incidental  to  equilibration  in  man,  the  commence- 
ment of  the  final  common  path  is,  as  we  have  seen,  located 
at  centres  higher  than  the  spinal  neurones,  e.g.,  in  centres 
located  in  the  cerebellum,  midbrain,  or  pons.  The  com- 
mencement of  the  final  common  paths  for  the  movements 
of  nystagmus  are  probably  located  in  the  cerebellum. 
Nystagmus  has  seldom  been  elicited  from  the  cerebral  cor- 
tex (Beevor  and  Horsley^*').  This,  however,  does  not 
mean  that  paths  do  not  originate  in  the  cerebral  cortex, 
which,  if  irritated  are  capable  of  causing  nystagmus,  for 
there  are  free  communications  between  the  cerebral  cortex 
and  the  cerebellar  centres. 

Nystagmus  is  a  highly  co-ordinated  complex  resulting 
from  associated  alternating  reflexes.  Sherrintgon  ^^  showed 
that  in  such  alternating  reflexes  the  antecedent  reflex 
"brings  about  the  stimulus  for  the  next  reflex,"  and 
predisposes  the  arc  of  the  next  reflex  to  react  to  the 
stimulus  when  it  arrives.  In  other  words  at  the  com- 
mencement of  the  final  common  path  of  the  succeeding 
reflex  the  threshold  for  afferent  impulses  is  lowered  during 
inhibition.  In  horizontal  nystagmus,  therefore,  during 
the  steady  deviation  of-  the  eyes  to  the  left,  preparation 
is  being  made  for  the  succeeding  reflex  movements 
whereby  the  eyeballs  are  turned  rapidly  toward  the  right. 
Inhibition  plays  an  important  part  in  this  preparation, 
although  afferent  impulses,  especially  those  generated  in 
the  receptors  of  the  labyrinth  and  of  the  ocular  muscles 
(and  in  the  retinal  receptors  in  purely  ocular  nystagmus) 
are  the  immediate  determining  factor  in  initiating  the 
movements.  Inhibition,  it  should  be  remembered,  does 
not  always  reduce  the  contraction  of  the  inhibited  muscle 


296  SEMICIRCULAR   CANALS 

to  zero.  This  lower  grade  of  contraction  in  the  muscles 
plays  an  important  part  in  physiological  nystagmus,  as 
it  does  elsewhere  in  the  muscular  mechanisms  of  the 
body.  Inhibition  may  give  place  to  excitation,  owing  to 
a  change  of  intraspinal  conditions.  Thus,  stimulation 
of  a  small  afferent  nerve  often  excites  a  reflex  movement 
of  alternating  direction,  i.e.,  extension  of  the  knee 
succeeds  primaiy  flexion.  Here  part  of  the  primary 
movement  was  inhibition  of  the  quadriceps  extensor,  and 
this  was  converted  into  extension  of  the  knee,  i.e.,  excita- 
tory action  of  the  quadriceps  extensor.  A  similar  conver- 
sion occurs  in  strychnin  poisoning,  as  well  as  under  the 
influence  of  cerebral  action  (Sherrington  ^^ ) . 

In  purely  ocular  nystagmus,  e.g.,  that  by  means  of 
which  a  person  sitting  or  standing  still  is  enabled  to  fix 
visually,  rapidly  passing  objects,  alternating  reflexes  are 
utilized  just  as  in  the  case  of  labyrinthine  nystagmus,  but 
in  purely  ocular  nystagmus,  stimuli  originating  in  the  re- 
tinal receptors  are  the  active  factors  in  determining  the 
nystagmus.  The  afferent  retinal  paths  are  in  relation 
with  the  same  final  common  paths  utilized  by  the  laby- 
rinthine receptors.  Frequently  the  labyrinthine  and  re- 
tinal arcs  act  as  allied  arcs,  as  where  a  person  standing  or 
sitting  still,  views  rapidly  passing  objects.  Here  a  quick 
turn  of  the  head  in  the  direction  opposite  to  that  of  the 
passing  objects  initiates  nystagmus  similar  in  every  re- 
spect and  serving  the  same  purpose  as  that  evoked  by  the 
retinal  receptors.  The  relation  of  alliance  between  the 
labyrinthine  and  retinal  arcs  is  further  manifested  by  the 
deterioration  in  function  which  the  labyrinthine  mechan- 
ism of  nystagmus  undergoes  in  persons  suffering  from 
complete  optic  atrophy.  In  several  of  these  patients  with 
good  hearing  and  good  powers  of  balancing,  nystagmus 
could  not  be  evoked  by  aural  irrigations  at  115°  F.,  al- 
though some  disturbance  of  the  equilibrium  with  devia- 
tion in  the  gait  was  effected.  Failure  to  evoke  nystagmus 
was  all  the  more  remarkable  in  these  cases,  as  the  patients 
were  comparatively  young,  e.g.,  from  forty  to  forty- five 
years. 

Every  reflex  is  purposive  (Sherrington),  and  the  two 
sets  of  reflex  movements  that  occur  in  nystagmus  have  evi- 
dently a  purposive  quality.     Thus  the ' '  short  movements' ' 


PHYSIOLOGY  297 

which  give  direction  to  the  nystagmus  are  executed  by 
means  of  clonic  contractions  of  such  rapidity  that  vision 
is  impossible  during  their  progress.  On  the  other  hand 
the  slow  movements  are  executed  under  tonic  contractions 
so  co-ordinated  that  photo  stimuli  have  time  to  affect  the 
retinal  receptors.  If  time  were  allowed  for  the  generation 
of  retinal  impulses  during  the  rapid  movements  of  nystag- 
mus, clear  continuous  vision  of  moving  objects  would  be 
an  impossibility.  Further  security  from  such  a  difficulty 
is  afforded  by  frequent  rapid  interruption  of  the  movement 
of  the  eyes  under  the  influence  of  the  short  jerks.  Hence 
the  latter  consist  of  clonic  contractions  frequently  inter- 
rupted by  slow  movements  of  short  duration  and  in  the 
opposite  direction.  Thus  even  in  the  excursions  of  the 
eyes  with  the  rapid  elements,  there  are  short  intermissions 
during  which  vision  is  possible.  These  intermissions 
avoid  the  confusion  and  possible  disorientation  that  might 
ensue  from  a  lapse  in  the  continuity  of  vision.  The  asso- 
ciated movements  of  the  head  and  upper  part  of  the  body 
may  be  similarly  accounted  for  by  the  reciprocal  innerva- 
tion that  obtains  upon  a  large  scale  between  wide  fields  of 
musculature  related  to  opposing  labyrinthine  receptors. 
The  commencement  of  the  final  common  paths  for  the  re- 
flexes involved  in  these  movements  are  situated  most 
probably  in  the  cerebellum  or  midbrain.  It  seems  that 
in  extensive  movements  of  equilibration  reciprocal  innerva- 
tion obtains  between  each  half  of  the  cerebellum,  so  that 
the  centres  in  one  half  are  inhibited  when  those  in  the 
opposite  half  are  stimulated,  and  vice  versa.  Later  we 
shall  see  that  there  is  reason  to  believe  that  centres  in  the 
cerebellum  and  midbrain  are  similarly  related  to  centres 
in  the  diencephalon  with  regard  to  certain  gross  movements 
of  station  and  progression. 

The  paths  along  which  impulses  controlling  the  move- 
ments of  the  eyes  travel  are  variously  spread.  The  affer- 
ent labyrinthine  connections  with  the  cerebellum  have  been 
traced  more  or  less  successfully,  and  the  relations  have  been 
found  to  be  in  the  main  crossed.  With  the  efferent  cere- 
bellar paths,  anatomists  have  not  been  so  successful. 
Many  observations  point  to  the  posterior  longitudinal  fas- 
ciculus as  carrying  numerous  efferent  cerebellar  paths. 
The  observations  of  Duval  and  Laborde  ^°  point  to  the  fact 


298  SEMICIRCULAR  CANALS 

that  the  fibres  of  the  posterior  longitudinal  fasciculus 
connect  the  third  with  the  sixth  nucleus  of  the  same  side. 
Bechterew  holds  that  the  fibres  to  the  sixth  nucleus  are 
the  continuations  of  those  from  the  cerebellum  to  the 
superior  olivary  nucleus,  and  Schafer "  denies  that  any 
fibres  pass  from  the  sixth  or  third  nucleus  to  the  posterior 
longitudinal  fasciculus.  The  conjugate  deviation  of  the 
eyes  that  occurs  on  stimulation  of  the  sixth  nucleus  is  to 
be  accounted  for  by  stimulation  of  paths  for  associated 
movements,  and  is  not  to  be  regarded  as  an  indication  of 
the  importance  of  this  centre  over  other  ocular  centres  in 
the  production  of  nystagmus.  There  are  numerous  other 
forms  of  ocular  deviations  the  most  rational  explanation 
of  which  seems  to  be  that  based  upon  the  vestibulo-cere- 
bellar  relations  described  in  these  chapters. 

The  afferent  paths  of  the  vestibular  apparatus,  in  so 
far  as  they  relate  to  the  complex  muscular  actions  con- 
cerned in  equilibration  with  the  associated  nystagmus  and 
other  adjustments,  are  mainly  related  directly  or  indirectly 
to  the  cerebellum.  It  has  been  seen  that  vestibular  fibres 
or  their  continuations  reach  other  structures.  Thus  the 
vestibular  apparatus  is  brought  into  relation  with  the  op- 
tic thalamus,  the  corpora  quadrigemina  and  perhaps  the 
auditory  cortex,  as  well  as  with  the  nuclei  of  other  nerves 
of  higher  and  lower  levels.  Such  connections  may  supply 
direct  paths  for  certain  co-ordinations,  yet  these  latter  are 
of  minor  importance  compared  with  those  requisite  for 
the  maintenance  of  equilibrium  which  are  carried  on 
mainly  under  cerebellar  influence.  The  connections  of 
the  labyrinth  (vestibular  nerve)  with  the  cerebellum  are 
established  as  follows : 

1.  By  paths,  interrupted  in  the  vestibular  nuclei  (in- 
cluding Deiters'),  to  the  roof  nucleus  (nucleus  fastigii) 
mainly  of  the  opposite  side. 

2.  By  way  of  the  vestibulo-olivo-cerebellar  tract,  i.e., 
after  interruption  in  Deiters'  nucleus  (or  perhaps  some 
fibres  pass  without  interruption)  to  the  inferior  olive  of 
the  same  side  across  to  the  olive  of  the  opposite  side,  and 
thence  through  the  restiform  body  to  the  cerebellum. 

These  vestibular  relations  with  the  cerebellum  are 
mainly  crossed.  Thus  far  we  have  traced  the  afferent 
labyrinthine  impulses  that  cause  nystagmus  and  disorders 


PHYSIOLOGY  299 

of  equilibrium  in  rotations,  etc. ,  to  the  opposite  half  of 
the  cerebellum,  stimulation  of  the  different  areas  of  which, 
in  the  region  of  the  central  lobe,  causes  phenomena  iden- 
tical with  those  that  are  produced  by  rotations,  aural  irri- 
gations, and  galvanism.  The  efferent  paths  along  which 
cerebellar  impulses  travel  to  impress  the  various  motor 
neurones  are  so  scattered  that  anatomists  have  not  been 
so  successful  in  tracing  them  as  they  have  been  in  the  case 
of  the  afferent  paths.  This,  however,  in  no  way  gainsays 
the  existence  of  such  connections.  These  efferent  paths 
are  therefore  grouped  with  the  undefined  paths  which  in- 
clude: (a)  fibres  from  the  cerebellum  to  the  posterior 
longitudinal  fasciculus  and  thence  to  other  centres  and 
especially  to  the  ocular  nuclei ;  (b)  fibres  to  the  cerebral 
cortex  as  well  as  to  the  various  centres  in  the  midbrain, 
pons,  medulla  and  cord  which  insure  co-ordinated  action 
of  ocular,  skeletal,  and  perhaps  visceral  muscles,  as  well  as 
of  the  great  centres  in  the  medulla,  viz. ,  vagus,  vaso-motor, 
respiratory,  etc. 

In  a  general  way  the  efferent  cerebellar  impulses  are 
distributed  to  the  motor  centres  situated  upon  the  same 
side  of  the  body.  In  the  case  of  eye  movements,  as  in 
horizontal  nystagmus  to  the  left,  the  slow  steady  move- 
ment is  caused  by  stimulation  (relative  or  absolute)  of  the 
area  situated  on  the  left  of  the  pyramid  of  the  middle  lobe 
whence  impulses  are  sent  by  way  of  the  posterior  longi- 
tudinal fasciculus  or  other  paths  to  the  sixth  nucleus  of 
the  same  side  and  simultaneously  to  the  group  of  cells  in 
the  third  nucleus  that  controls  the  internal  rectus  of  the 
opposite  side.  Coincident  with  this  stimulation  of  the 
area  on  the  left  of  the  pyramid  of  the  middle  lobe  there 
is  active  inhibition  of  the  mechanisms  controlling  hori- 
zontal eye-movements  toward  the  right.  The  site  of  this 
inhibition  is  at  or  near  the  commencement  of  the  final 
common  path,  most  probably  situated  in  this  instance  in 
the  corresponding  cerebellar  centres  to  the  right  of  the 
pyramid  of  the  middle  lobe.  The  impulses  causing  the 
inhibition  pass  by  collaterals  or  main  stems  from  the  af- 
ferent cerebellar  (vestibular,  etc.)  paths  that  join  the 
corresponding  cerebellar  centres  upon  the  left  side.  The 
chief  reason  for  thus  setting  up  the  cerebellar  ocular  cen- 
tres of  one  side  in  reciprocal  relation  with  the  correspond- 


300  SEMICIRCULAR  CANALS 

ing  centres  upon  the  other  side  are  supplied  by  the  phe- 
nomena observed  in  bilateral  aural  irrigations,  where  there 
was  absence  of  horizontal  nystagmus,  and  in  rotations  fol- 
lowing cold  aural  irrigations,  where  there  was  likewise  a 
similar  absence  of  horizontal  nystagmus.  This  view  is 
strengthened  by  the  results  following  removal  of  the  whole 
or  of  part  of  the  cerebellum.  Thus  after  removal  of  one 
lateral  lobe  of  the  cerebellum,  there  was  nystagmus  for  a 
day  or  two,  whilst  after  removal  of  the  whole  cerebellum 
there  was  no  nystagmus  but  only  nystagmoid  movements 
on  attempts  at  voluntary  movements  of  the  eyes  (Risien- 
Russell  60) .  ^ 

As  previously  stated,  the  reflex  arcs  on  either  side  of 
the  body,  controlling  the  movements  of  horizontal  nystag- 
mus, function  in  an  alternating  manner  so  that  during  the 
period  of  inhibition  the  threshold  value  is  lowered  at  the 
commencement  of  the  final  common  path  on  the  inhibited 
side.  After  a  time  the  lowered  threshold  value,  aided 
probably  by  summation  of  subminimal  afferent  labyrin- 
thine, retinal,  or  other  stimuli,  results  in  conversion  of  the 
inhibition  into  excitation  with  a  corresponding  conversion 
of  excitation  into  inhibition  at  the  commencement  of  the 
corresponding  final  common  path  on  the  opposite  side. 
Thus  nystagmus  has  its  foundation  in  alternating  reflexes 
which,  when  once  initiated,  tend  to  continue  as  each  re- 
flex prepares  the  way  for  its  successor.  Alternating  re- 
flexes are,  however,  cut  short  with  ease,  hence  voluntary 
fixation  of  the  eyes  tends  to  check  nystagmus.  This  is 
especially  the  case  where  the  eyes  are  strongly  deviated  to 
the  side  toward  which  the  slow  elements  are  directed. 
The  reason  why  turning  the  eyes  voluntarily  to  this  side 
is  so  effective  in  checking  nystagmus  rests  upon  the  fact 
that  voluntary  fixation  is  more  readily  affected  in  this 
position  owing  to  the  increased  cerebellar  tonus  upon  that 
side  which  acts  as  adjuvant  to  the  impulses  from  the  motor 
cortex  of  the  opposite  side.  An  additional  reason  is 
found  also,  perhaps,  in  cerebral  influence  which,  like 
strychnin  poisoning,  can  convert  inhibition  into  excita- 
tion in  the  spinal  motor  neurones  (Sherrington  ^3). 

In  vertical  nystagmus  toward  the  feet  the  anterior  por- 
tion of  the  middle  lobe  is  stimulated  (relatively  or  abso- 
lutely) ,  with  the  result  that  the  eyes  are  drawn  steadily 


PHYSIOLOGY  301 

toward  the  vertex.  When  this  excursion  has  been  com- 
pleted, the  alternating  return  movement  toward  the  feet  is 
executed  in  jerks,  owing  to  influences,  similar  to  those 
described  for  horizontal  nystagmus,  affecting  the  posterior 
portion  of  the  middle  lobe  in  which  are  located  the  centres 
for  drawing  the  eyes  toward  the  feet.  It  is  thus  seen  that 
rotations  in  the  mesial  plane  ' '  face  first' '  and  hot  bilateral 
aural  irrigations  have  the  same  effect  as  stimulation  of  the 
anterior  portion  of  the  middle  lobe  of  the  cerebellum, 
whilst  rotations  in  the  mesial  plane  "occiput  first"  and 
cold  bilateral  aural  irrigations  have  the  same  effect  as 
stimulation  of  the  posterior  part  of  the  middle  lobe.  In 
vertical  nystagmus,  the  efferent  cerebellar  impulses  reach 
the  nuclear  group  on  either  side  of  the  middle  line  con- 
trolling the  muscles  involved  in  the  movements. 

In  rotary  nystagmus  the  cerebellar  areas  affected  are 
located  in  the  region  of  the  flocculus  and  lateral  lobe 
(semilunar  lobule).  In  rotary  nystagmus  against  the 
watch  the  efferent  impulses  controlling  the  slow  element 
are  sent  to  the  fourth  nucleus  on  the  left  side  which,  on 
account  of  the  decussation  of  the  fourth  nerve,  supplies 
the  right  superior  oblique.  At  the  same  time  correspond- 
ing impulses  are  sent  to  the  group  of  cells  in  the  third 
nucleus  controlling  the  left  inferior  oblique.  When  the 
excursion  in  the  direction  of  the  hands  of  the  watch  has 
been  completed  under  the  influence  of  stimulation  of  some 
area  in  the  region  of  the  flocculus  or  lateral  lobe  (semilunar 
lobule) ,  the  return  movement  in  the  direction  against  the 
hands  of  the  watch  is  made  in  rapid  jerks  owing  to  influ- 
ences, similar  to  those  described  for  horizontal  nystagmus, 
affecting  analogous  areas  in  the  flocculus  or  lateral  lobe 
upon  the  opposite  side  which  control  the  muscles  involved 
in  the  movement,  i.e.,  the  left  superior  oblique  and  the 
right  inferior  oblique. 

It  may  be  noted  that  the  direction  of  the  movements 
of  the  eyes  in  rotary  nystagmus  is,  at  times,  difficult  to 
determine,  for  frequently  the  jerky  motions  are  slow  enough 
to  permit  actual  vision  and  strongly  turning  the  eyes  in 
one  direction  or  another  may  so  alter  the  movement  that 
study  with  the  ophthalmoscope  becomes  difficult  or  fruit- 
less. 

The  efferent  cerebellar  paths  involved  in  vertical  and 


302  SEMICIRCULAR  CANALS 

rotary  nystagmus  probably  pass  by  way  of  the  superior 
peduncle  and  posterior  longitudinal  fasciculus.  It  is  not 
necessary,  as  Schafer  seems  to  think,  that  the  fibre  paths 
of  the  posterior  longitudinal  fasciculus  be  traced  outward 
from  the  motor  nucleus  toward  the  muscle.  It  is  suffi- 
cient if  the  fibres  reach  the  nucleus  and  impress  the  motor 
neurones. 

The  flexible  mobility  of  the  eye  is  such  that  deviations 
and  rotations  can  take  place  to  a  limited  extent  in  almost 
every  conceivable  direction.  It  is,  therefore,  highly  prob- 
able that  whilst,  in  the  main,  the  ampullary  receptors  of 
each  semicircular  canal  are  chiefly  affected  by  rotations  in 
one  plane,  they  are  also  to  a  lesser  extent  perhaps  affected 
by  movements  in  several  other  planes,  each  of  which  in 
turn  is  associated  with  definite  cerebellar  centres  for  ocu- 
lar tonus  control.  The  grounds  for  this  assumption  are 
to  be  found  in  the  diagonal  deviations  in  Ferrier's  experi- 
ments on  stimulating  certain  cerebellar  areas,  e.g.,  to  the 
left  of  the  middle  line  in  posterior  superior  lobes,  and  in 
the  diagonal  nystagmus  noted  upon  rotations  in  diagonal 
planes,  traces  of  which  are  occasionally  met  with  in  aural 
irrigations  and  in  galvanism. 

The  cerebellar  balanced  mechanisms  are  so  related  to 
the  cerebral  mechanisms  that  each  half  of  the  cerebellum 
acts  in  conjunction  with  the  opposite  cerebral  hemisphere. 
Thus  each  half  of  the  cerebellum  controls  the  muscles  that 
turn  the  eyes  in  a  certain  direction,  e.g.,  in  lateral  move- 
ments toward  the  same  side  and  inhibits  the  muscles  that 
move  the  eyes  in  the  opposite  direction.  The  centres  for 
certain  movements  (e.g.,  the  vertical)  are,  however,  not 
represented  in  one  side  of  the  cerebellum  as  opposed  to 
the  other,  but  are  grouped  about  the  median  line  in  one 
portion  of  the  vermis,  whilst  the  centres  for  the  antago- 
nistic movements  are  grouped  about  the  middle  line  in  an- 
other area  of  the  vermis.  The  cerebellar  mechanisms  act 
purely  in  a  reflex  manner.  Tlieir  afferent  and  efferent 
limbs  have  widespread  connections  on  account  of  the  ex- 
tensive influence  the  cerebellum  exerts  on  various  muscu- 
lar activities. 

The  chief  afferent  cerebelhir  paths  are  those  related  to 
the  labyrinthine  and  retinal  receptors,  and  to  the  cerebral 
cortex,  and  the  peripheral   structures  concerned    in  the 


PHYSIOLOGY  BOB 

muscle  sense  (Golgi-Mazzini  organs,  etc.).  The  relations 
of  the  cerebellum  to  the  labyrinth,  organs  of  muscular 
sense,  and  to  the  various  nuclei  of  the  sensory  nerves  have 
been  sufficiently  discussed.  The  relations  to  the  cerebral 
cortex  are  made  through  paths  that  convey  impulses  in 
both  directions.  Stimulation  of  the  frontal  ocular  area 
sends  impulses  to  the  opposite  half  of  the  cerebellum,  after 
the  manner  in  which  labyrinthine  impulses  reach  the  con- 
tralateral half  of  the  cerebellum.  Probably  afferent  cere- 
bellar impulses  which  originate  in  various  parts  of  the 
cerebral  cortex,  e.g.,  frontal,  temporal,  and  occipital,  nor- 
mally control  the  related  cerebellar  mechanisms.  The  cere- 
bral cortex  in  this  instance  acts  somewhat  after  the  man- 
ner of  sensory  peripheral  mechanisms  in  relation  to  the 
cerebellum.  Pisien-Russell's  ^^  observations  seem  to  war- 
rant this  conclusion.  This  physiologist  removed  part  ot 
the  frontal  ocular  areas  and  subsequently  removed  the  lat- 
eral lobe  of  the  cerebellum  on  the  same  side.  In  this 
instance  the  last  part  of  the  operation  w^as  followed  by  much 
less  deviation  of  the  eyeballs  to  the  sound  side  than 
would  be  obtained  ordinarily  by  removal  of  the  lateral 
lobe  of  the  cerebellum  alone. 

The  efferent  limbs  of  the  cerebellar  mechanisms  are 
scattered  widespread  on  their  way  to  the  different  spinal 
motor  neurones  which  they  influence.  They  cannot  there- 
fore be  readily  differentiated  anatomically  from  the  affer- 
ent limbs.  In  a  general  way,  however,  they  are  related 
to  the  muscles  upon  that  side  of  the  body  in  which  the 
cerebellar  neurones  from  which  they  spring  are  located. 

Efferent  cerebellar  paths  also  carry  impulses  to  the 
various  regions  of  the  cerebral  cortex  from  which  in  turn 
spring  afferent  cerebellar  paths.  It  is  by  means  of  these 
paths  running  in  both  directions  between  the  cerebrum 
and  the  cerebellum  that  these  two  organs  act  in  harmony 
in  the  complex  processes  involved  in  ocular  movements, 
and  in  movements  of  equilibration.  Risien-Russell,  ^^  as 
before  stated,  has  shown  that  the  cerebellum  exerts  a 
marked  influence  upon  the  related  centres  in  the  cerebral 
cortex  one-sided  lesion  of  the  former  causing  increased 
irritability  in  the  opposite  cerebral  hemisphere.  Luciani, 
however,  concluded  that  excitability  was  increased  in  some 
points  and  in  others  depressed.     It  is  by  means  of  this 


804  SEMICIRCULAR   CANALS 

functional  relation  that  the  cerebrum  is  enabled  to  com- 
pensate most  economically  for  temporary  or  permanent 
defect  of  the  cerebellar  mechanisms.  This  relationship 
perhaps  accounts,  in  part,  for  the  well-known  defective 
cerebral  development  which  accompanies  congenital  cere- 
bellar defects.  It  also  seems  to  have  some  bearing  upon 
the  nystagmus  and  vertigo  seen  at  times  in  patients  suffer- 
ing from  manic-depressive  psychosis,  although  in  the  only 
case  observed  by  the  author  there  was  also  present  a  slight 
aural  defect.  In  this  case  which  was  of  the  mixed  type, 
the  probable  explanation  of  the  phenomenon  was  that  com- 
pensation for  the  defect  in  the  vestibulo-cerebellar  mechan- 
isms had  been  made  but  the  supervention  of  the  manic- 
depressive  psychosis  acted  somewhat  after  the  manner  that 
ether  or  chloroform  narcosis  acts  in  dogs  in  which  com- 
pensation has  been  established  after  removal  of  portions 
of  the  cerebrum  or  cerebellum,  causing  a  reappearance  of 
the  cerebellar  or  cerebral  defect.  No  opportunity  was 
afforded  of  studying  thoroughly  the  labyrinthine  reac- 
tions. 

Besides  the  nystagmus  there  were  other  signs  of  cere- 
bellar disturbance,  such  as  vomiting,  vertigo,  and  general 
muscular  weakness.  The  nystagmus  disappeared  with 
these  in  a  short  time  (about  two  weeks)  as  the  patient  im- 
proved somewhat  in  general  mental  and  physical  health. 

The  conclusions  are: 

1.  That  nystagmus  in  rotations  is  a  co-ordinated  move- 
ment, executed  reflexly  by  means  of  afferent  labyrinthine 
impressions  acting  upon  centres  situated  in  and  about  the 
middle  lobe  of  the  cerebellum  and  intended  to  aid  in 
the  compensatory  adjustments  of  rotations  as  well  as  in  the 
visual  fixation  of  rapidly  passing  objects. 

2.  That  the  ampullaiy  receptors  of  each  semicircular 
canal  have  definite  relations  with  certain  portions  of  the 
cerebellum  in  the  vicinity  of  the  middle  lobe,  viz.,  the 
ampullary  receptors  of  the  left  and  right  horizontal  canals 
with  the  centres  situated  to  the  right  and  left  respectively 
of  the  pyramid  of  the  middle  lobe  (pyramis  vermis)  ; 
those  of  the  paired  j^osterior  and  superior  canals  with  the 
centres  situatf^d  about  the  middle  line  of  the  posterior  and 
anterior  portions  respectively  of  the  middle  lobe ;  and  those 
of  the  superior  and  posterior  canals  taken  individually  or 


PHYSIOLOGY  805 

in  crossed  pairs  with  the  centres  located  in  the  region  of 
the  flocculus  and  lateral  lobes. 

3.  That  by  means  of  these  relations  and  the  correspond- 
ing nystagmus  a  guide  may  be  had  in  localizing  peripheral 
vestibular  nerve  lesions  and  lesions  of  the  cerebellum. 


CHAPTER  XXI 

RELATIONS  OF  THE  SEMICIRCULAR  CANALS  TO  THE 

OCULO-MOTOR  NUCLEI  AND  THEIR  BEARING  UPON 

THE  RESULTS  OF  CERTAIN  EXPERIMENTS 

The  phenomena  following  section  of  the  vestibularis  in 
the  sheep  (Biehl  '^^)  have  already  been  somewhat  discussed. 
It  remains  to  consider  the  ocular  phenomena  in  the  light 
of  the  relations,  just  established,  of  the  semicircular  canals 
to  the  oculo-motor  nuclei.  The  crossed  relation  of  each 
labyrinth  to  the  fourth  nucleus  and  that  portion  of  the 
third  nucleus  governing  the  action  of  the  associated  inferior 
oblique  afford  a  ready  explanation  for  the  skew  deviation. 
A  glance  at  the  diagram  of  these  relations,  page  288, 
shows  that  section  of  the  right  vestibular  nerve  cuts  off 
the  afferent  vestibular  tonus  impulses  to  the  VI  and  IV 
nuclei  on  the  left  side,  as  well  as  those  to  that  part  of 
the  III  nucleus  controlling  the  right  internal  rectus  and 
the  left  inferior  oblique.     The  effect  is : 

1.  Paresis  of  the  left  external  rectus  and  of  the  asso- 
ciated right  internal  rectus,  causing  a  general  tendency  of 
the  eyeballs  to  turn  toward  the  right. 

2.  Paresis  of  the  right  superior  and  left  inferior 
oblique,  thereby  leaving  the  eyeballs  under  the  unopposed 
control  of  the  right  inferior  and  of  the  left  superior  oblique 
in  conjunction  with  the  right  rectus  externus  and  the  left 
rectus  internus. 

The  net  result  is  that  the  right  eye  is  drawn  downward 
and  outward,  and  the  left  eye  upward  and  inward.  (See 
diagram.)  In  section  of  the  vestibular  nerve  in  the  dog, 
Bechterew  ^^  observed  similar  deviations  of  the  eyes.  Sec- 
tion of  both  vestibular  nerves  causes  no  ocular  deviations 
— the  eyes  assuming  the  primary  position. 

The  recorded  phenomena  following  irritation  of  the 
vestibular  nerve  are,  for  the  most  part,  untrustworthy. 

306 


PHYSIOLOGY  307 

The  twofold  element  of  motion  in  the  nystagmus  that  ac- 
companies irritation  of  the  vestibular  nerve  has  been  a 
source  of  confusion,  so  that  many  observers  reached  widely 
divergent  conclusions.  Hence  the  phenomena  attributed 
to  irritation  of  the  canals  or  of  the  divided  vestibular 
nerve  have  to  be  taken  with  extreme  caution.  In  the 
study  of  this  phase  of  the  question  it  seems  that  clinical 

v;  ot-  —  ovi 


ER-*- 


ZR 


BK 


Diagram  showing  the  effect  upon  the  ocular  muscles  in  section 
of  the  right  vestibular  nerve.  The  minus  sign  indicates 
absence  of  vestibulo-cerebellar,  i.e.,  labyrinthine  tonus, 
and  the  positive  sign  indicates  a  relative  excess  of  ves- 
tibulo-cerebellar tonus.  Ill,  IV,  and  VI  indicate  the  motor 
nuclei  of  the  eyeballs.  SO,  superior  oblique ;  10,  inferior 
oblique  ;  IR,  internal  rectus ;  ER,  external  rectus  ;  RE,  right 
eye ;  LE,  left  eye. 

methods  have  the  advantage  and  are  more  trustworthy 
than  those  of  the  laboratory.  This  should  be  an  omen 
and  incentive  to  the  mere  practitioner. 

Sheep  and  dogs,  in  which  the  vestibular  nerve  upon 
one  side  has  been  divided,  endeavour  to  lie  upon  the  side 
of  operation,  for  in  this  position  the  actual  tonus  effect  of 
the  opposite  labyrinth  is   reduced  to  a  minimum,   the 


308  SEMICIRCULAR   CANALS 

muscles  under  its  control  being  at  rest.  There  is  there- 
fore less  need  for  tonus  innervation  from  the  labyrinth  on 
the  side  of  operation.  In  this  position  the  limbs  of  the  side 
of  operation  were  relaxed,  whilst  those  of  the  opposite  side 
were  lengthened  (and  stiff)  (Bechterew  ^^)  due  no  doubt 
to  cerebral  motor  influence,  as  Sherrington  ^^  observed 
that  lying  upon  the  side  tends  to  relax  (the  reflex)  tonus 
of  the  extensor  muscles.  Lying  on  the  back  the  difference 
between  the  two  sides  was  less  apparent.  In  positions 
upon  the  side,  therefore,  there  is  evidence  of  some  func- 
tional activity  of  the  labyrinthine  mechanisms  probably 
concerned  in  slight  equilibratory  adjustments.  This  point 
is  emphasized  in  seasickness  and  related  conditions,  where 
turning  from  the  back  upon  the  side  may  be  sufficient  to 
determine  impending  vomiting.  When  the  animal  lying 
on  the  side  of  operation  lifted  its  head  from  the  ground 
or  made  the  slightest  movement,  nystagmus  occurred  or  if 
already  present  it  became  aggravated.  If  the  animal  re- 
covered sufficiently  to  stand  it  was  easily  pushed  over  from 
the  sound  side,  whilst  the  immediate  effects  of  the  opera- 
tion were  rolling  movements  about  the  long  axis  to  the 
side  of  operation.  Hence  there  was,  after  section  of  the 
right  vestibular  nerve  in  the  sheep,  a  weakness  or  devia- 
tion of  the  head  and  body  toward  the  side  of  operation, 
with  a  tendency  to  rotate  in  the  same  direction  (in  man, 
from  right  to  left  and  with  a  mixed  nystagmus  the  hori- 
zontal element  being  directed  to  the  left  and  the  rotary 
element  with  the  watch,  all  of  which  correspond  exactly 
with  the  phenomena  of  cold  irrigation  of  the  right  ear,  or 
of  hot  irrigation  of  the  left  ear,  or  with  the  primary  phe- 
nomena of  rotations  about  the  long  axis  from  right  to  left 
or  the  secondary  phenomena  of  similar  rotations  from  left 
to  right;  or  with  the  phenomena  that  accompany  closure 
of  the  circuit  with  the  anode  over  the  right  mastoid  or 
with  the  cathode  over  the  left  mastoid.  The  muscles 
which  execute  these  movements  are  mainly  situated  upon 
the  right  side  (i.e.,  on  the  side  of  operation)  and  are 
mainly  in  relation  with  the  labyrinth  of  the  opposite  side. 
Normally,  impulses  from  each  labyrinth  counterbalance 
each  other  in  the  adjustments  necessary  for  the  mainten- 
ance of  equilibrium.  Any  material  interference  with  the 
labyrinthine  receptors,   whereby   the  threshold  value  of 


PHYSIOLOGY  809 

etimnli  originating  normally  in  response  to  movements  or 
displacements  of  equilibrium  are  enhanced  or  depressed 
on  one  side  or  the  other  will  cause  disturbances  similar  to 
those  following  section  of  the  vestibular  nerve. 

The  constant  tonus  effect  of  the  labyrinth  upon  the 
muscles  has  therefore  been  demonstrated.  The  crossed 
functional  relation  between  the  labyrinth  and  the  muscu- 
lature of  the  opposite  side  must  be  admitted  (though 
V.  Bechterew  denies  this) ,  and  finally,  the  evidence  seems 
overwhelming  that  the  main  functional  and  anatomical 
relation  between  the  labyrinth  and  the  cerebellum  is  a 
crossed  one. 

This  view  of  the  crossed  relation  of  the  vestibular  ap- 
paratus receives  corroboration  from  the  results  of  various 
observers.  There  is  anatomical  and  physiological  evidence 
that  the  cerebellum  is  in  crossed  relation  with  the  cerebral 
cortex,  optic  thalamus,  red  nucleus  and  other  important 
centres,  and  with  the  peripheral  organs  for  afferent  visual, 
labyrinthine,  including  auditory,  and  perhaps  to  some  ex- 
tent, tactual,  muscular  and  other  impressions. 

Luciani  ^^  and  Risien- Russell  ^°  observed  phenomena 
similar  in  general  to  those  that  follow  section  of  the  ves- 
tibularis, but  with  the  movements  toward  the  sound  side 
after  ablation  of  one-half  of  the  cerebellum.  Section  of  the 
middle  cerebellar  peduncle  causes  rolling  movements 
toward  the  sound  side  (v.  Bechterew,  Schiff,  Lussana, 
Longet  and  others).  Here  it  should  be  noted  that  the 
afferent  middle  peduncular  paths,  i.e.,  to  the  cerebellum, 
are  severed  mainly  after  decussation,  whilst  the  efferent 
paths  of  the  peduncle  which,  through  double  decussation, 
are  mainly  in  relation  with  the  muscles  on  the  same  side 
of  the  body  are  cut  before  any  decussation  has  taken  place. 
The  resulting  movements  are  the  same  as  those  which 
would  follow  section  of  the  same  afferent  paths  on  the 
other  side  of  the  body  before  decussation  had  taken  place. 
In  this  latter  event  the  movements  would  be  toward  the 
side  of  injury  as  in  the  case  of  section  of  the  vestibularis. 
Again,  section  of  the  vestibular  paths,  after  crossing  the 
middle  line,  if  such  a  thing  were  feasible,  would  beget 
movements  toward  the  sound  side  which  is  exactly  what 
follows  ablation  of  one-half  of  the  cerebellum.  After  sec- 
tion of  the  vestibularis,  stimulation  of  the  proximal  stump 


310  SEMICIRCULAR   CANALS 

causes  rotation  of  the  body  on  the  long  axis  toward  the 
sound  side.  This  points  to  a  relatively  enhanced  cere- 
bellar tonus  upon  the  side  related  to  the  stimulated  stump 
and  consequent  determination  of  the  body  movements  to- 
ward that  side,  i.e.,  toward  the  sound  side. 

Section  of  the  superior  cerebellar  peduncles  causes  no 
distinct  disturbances  of  equilibrium  (v.  Bechterew  ^^) . 
However,  circular,  instead  of  rolling  movements  were  ob- 
served with  lateral  deviation  of  the  eyes  toward  the  side 
of  operation  after  section  betw^een  the  cerebellum  and  cor- 
pora quadrigemina,  whilst  section  between  the  corpora 
quadrigemina  and  the  optic  thalamus  caused  deviation  to 
the  healthy  side  with  nystagmus.  Section  of  the  fibres 
passing  below  the  Sylvian  aqueduct  in  their  course  from 
the  postero-lateral  wall  of  the  third  ventricle  to  the  antero- 
external  part  of  the  floor  of  the  fourth  ventricle,  as  well  as 
section  of  the  middle  cerebellar  peduncle  caused  rolling 
movements  in  the  direction  of  the  sound  side  (v.  Bech- 
terew  ^^) .  Ferrier  ^  believes  these  phenomena  were  caused 
in  reality  by  interruption  of  the  paths  in  the  superior 
peduncle  or  by  injury  of  the  oculo-motor  nuclei  or  by  a 
combination  of  both  of  these  factors.  The  phenomena  ob- 
served by  v.  Bechterew  in  experimental  lesions  of  the  third 
ventricle  were  such  as  led  him  to  believe  that  in  this  ven- 
tricle resides  another  organ  of  equilibrium.  As  the  third 
ventricle  is  so  closely  related  to  the  optic  thalami  the  re- 
lations of  which  are  in  turn  so  widespread,  and  to  affer- 
ent optic  paths  on  their  way  to  the  cerebellum  (Panse  ^^^), 
it  is  very  probable  the  phenomena  were  due  to  lesions  of 
the  optic  fibre  paths  or  of  paths  to  or  from  the  optic  thai- 
ami.  Moreover  the  fibres  and  nucleus  of  the  posterior 
longitudinal  fasciculus  invade  to  some  extent  the  terri- 
tory of  the  third  ventricle. 

As  the  superior  peduncles  begin  to  decussate  at  the  level 
of  the  lower  (caudal)  border  of  the  inferior  colliculi,  it  is 
evident  that  in  v.  Bechterew's  division  of  the  peduncle 
between  the  corpora  quadrigemina  and  the  cerebellum, 
and  between  the  corpora  quadrigemina  and  the  optic  thal- 
amus the  effect  of  the  lower  section  on  one  side  would  be 
practically  equivalent  to  section  at  a  level  above  the  quad- 
rigemina on  the  other  side.  v.  Bechterew  believes  the 
Bujjerior  cerebellar  peduncle  completely  decussates.     The 


PHYSIOLOGY  311 

mc  st  generally  accepted  opinion  is  that  most  of  the  fibres 
of  the  peduncle  cross  at  the  decussation.  Above  the  de- 
cussation most  of  the  fibre  paths  are  interrupted  in  the 
red  nucleus,  those  not  so  interrupted  passing  through  the 
subthalamic  region  to  end  about  the  cells  of  the  thalamus. 
Most  of  the  fibre  paths  interrupted  in  the  red  nucleus  are 
continued  by  rubral  neurones  to  the  thalamus.  From  the 
thalamus  the  uninterrupted  paths,  as  well  as  those  inter- 
rupted in  the  red  nucleus,  are  continued  to  the  cerebral 
cortex.  Many  of  the  fibre  paths  interrupted  in  the  red 
nucleus,  however,  are  diverted  into  the  rubro-spinal  tract, 
which  traverses  the  brain  stem  and  antero-lateral  ground 
bundles  of  the  cord  to  reach  the  ventral  root  cells.  These 
fibres,  owing  to  Forel's  decussation,  recross  the  middle  line 
thus  bringing  the  half  of  the  cerebellum  in  which  the  fibre 
paths  originate  into  relation  with  the  muscles  of  the  same 
side  of  the  body.  It  does  not  matter  at  what  point  the 
reflex  cerebellar  tonus  arc  is  broken,  whether  in  the  affer- 
ent or  efferent  limb  the  effect  is  the  same,  i.e.,  loss  of 
tonus  of  the  muscles  supplied,  and  consequent  disturbance 
of  functional  precision  in  other  co-ordinating  centres,  es- 
pecially those  situated  in  the  optic  thalamus  and  cerebral 
cortex.  Hence  section  of  the  superior  peduncle  by  Ferrier, 
and  lesions  of  the  optic  lobes,  as  well  as  of  the  fibres  con- 
necting them  with  the  oculo-motor  nuclei  were  followed 
by  movements  toward  the  healthy  side.  Since  the  lesion 
in  section  of  the  superior  peduncle  is  situated  at  a  point 
where  decussation  has  already  taken  place  in  the  case  of 
the  afferent  paths,  and  where  it  has  not  yet  occurred  in  the 
case  of  the  efferent  paths,  which,  in  the  case  of  paths 
making  for  the  spinal  cord  owing  to  a  double  decussation, 
are  in  relation  Avith  the  muscles  of  the  same  side  of  the 
body,  the  phenomena  are  altogether  analogous  to  those 
following  hemi-extirpation  of  the  cerebellum  of  the  same 
side  or  section  of  the  middle  peduncle  of  the  same  side 
or  section  of  the  vestibular  nerve  after  decussation,  if  such 
a  thing  were  possible.  Interference  with  the  fibre  paths  of 
the  superior  peduncle  destined  for  the  thalamus  and  cere- 
bral cortex  causes  disturbance  of  the  cerebello-coi-tical  cir- 
cuit, whereby  the  animal  is  misinformed  not  only  as  to  his 
relations  in  .«pace,  but  also  as  to  the  degree  of  innervation 
jDLecessary  to  js^ntrol  certain  voluntary  movements  in  the 


812  SEMICIRCULAR  CANALS 

adjustments  of  equilibration.  This  tends  to  aggravate  the 
vertigo  caused  from  interference  with  the  other  parts  men- 
tioned above  (afferent  and  rubro-spinal  paths) .  The  re- 
sult is  that  the  animal  in  a  general  way  moves  or  rolls  in 
the  direction  of  the  sound  side,  the  musculature  of  which 
is  in  relation  with  the  intact  functioning  side  of  the 
cerebellum.  This  brings  that  particular  side  of  the  cere- 
bellum to  a  condition  of  rest  when  the  sense  of  vertigo  is 
at  a  minimum.  Again  this  is  exactly  what  the  sheep  or 
dog  with  the  divided  vestibular  nerve  does,  viz.,  seeks 
that  position  in  which  the  muscles  connected  with  the  half 
of  the  cerebellum  that  has  all  the  afferent  and  efferent  paths 
of  its  tonus  mechanisms  intact,  thereby  reducing  to  a 
minimum  the  subjective  and  objective  disturbances  that 
spring  from  injury  to  one  or  other  of  its  main  afferent  or 
efferent  i3aths.  The  site  of  the  lesion,  i.e.,  whether  it  is 
situated  on  one  side  or  the  other  of  the  median  line  is  not 
what  determines  the  direction  of  the  movement,  for  in 
many  instances  the  same  fibre  paths  may  be  divided  be- 
fore or  after  crossing  the  middle  line.  The  cerebellar 
centres  involved  are  the  all-important  thing  in  determining 
the  direction  of  the  ocular  and  bodily  deviations  which, 
in  a  general  way,  are  always  away  from  the  side  of  the 
cerebellum  with  which  the  injured  afferent  or  efferent  paths 
are  connected.  If  this  rule  be  kept  in  mind,  the  explana- 
tion of  clinical  and  experimental  phenomena  will  be  greatly 
facilitated.  The  conjugate  deviation  seen  in  extensive 
cerebral  hemorrhage  can  be  readily  explained  when  the  in- 
timate relation  of  each  half  of  the  cerebellum  with  the  op- 
posite cerebral  hemisphere  is  understood.  A  large  hemor- 
rhage over  one  cerebral  hemisphere  not  only  inhibits  the 
motor  centres  in  the  cerebral  ocular  areas  on  that  side, 
but  cuts  off  all  or  many  of  the  impulses  to  and  from  the 
cerebellum  by  way  of  the  related  superior  and  middle 
peduncles.  The  result  is  equivalent  to  section  of  such 
peduncles  after  decussation,  which  means  suspension  to  a 
certain  extent,  of  the  reflex  activity  of  the  related  cere- 
bellar centres  on  the  sound  side.  The  hnlf  of  the  cere- 
bellum on  the  side  of  the  cerebral  lesion  has  unrestricted 
play,  and  the  related  ocular  mechanisms  by  their  enhanced 
relative  tonus  to  the  oculo-mc^tor  muscles  t(md  to  turn  the 
eyes  in  a  general  way  toward  the  side  of  the  cerebral 


PHYSIOLOGY  813 

lesion.  The  turning  of  the  eyes  in  this  instance  toward 
the  side  of  the  lesion  is  analogous,  in  general  direction, 
to  the  turning  of  the  eyes  that  follows  section  of  the  ves- 
tibular nerve,  that  is,  toward  the  side  of  the  lesion,  but 
away  from  the  side  of  the  cerebellum  in  which  the  centres 
affected  by  the  lesion  are  located.  The  turning  of  the 
head  in  the  conjugate  deviation  of  cerebral  apoplexy  is 
due  to  suspension  of  function  of  centres  located  near  the 
frontal  ocular  centres  with  which  they  frequently  act  in 
conjunction,  as  in  the  common  associated  movements  of 
turning  the  head  and  eyes  to  one  side  or  the  other. 
Ferrier  ^  found  that  stimulation  of  the  general  frontal  ocu- 
lar area  on  one  side  caused  the  head  and  eyes  to  turn 
toward  the  opposite  side.  Later,  Beevor  and  Horsley*^ 
separated  the  centres  for  the  head  movement  from  those  of 
the  eye  movement.  Destruction,  therefore,  of  this  region 
or  inhibition  of  the  centres  contained  therein,  naturally 
causes  a  turning  of  the  head  and  eyes  toward  the  side  of 
the  lesion.  It  should  be  stated,  however,  that  Longet,^^! 
Lafarge,272  Lusanna,^^^  and  others  found  that  section  of  the 
superior  peduncle,  after  it  has  crossed  the  middle  line  as 
it  lies  in  the  tegmentum,  caused  rolling  on  the  long  axis 
to  the  sound  side,  whilst  section  of  the  peduncle  before  de- 
cussation near  its  exit  from  the  cerebellum  caused  rota- 
tion to  the  side  of  the  lesion.  In  estimating  the  import 
of  these  and  all  other  operations  upon  the  cerebellum  or 
its  peduncles,  the  distinction  between  phenomena  attribut- 
able to  irritation  and  those  attributable  to  destruction 
must  ever  be  kept  in  mind  as  well  as  the  distinction  be- 
tween movements  which  are  purely  automatic  and  those 
due  to  voluntary  compensation. 

We  have  seen  that  the  experimental  phenomena  con- 
nected with  lesions  of  the  cerebellum  and  of  the  superior 
and  middle  peduncles,  as  well  as  with  section  of  the  ves- 
tibular nerve,  point  strongly  to  the  fact  that  the  peduncles 
mentioned  contain  paths  for  the  transmission  of  impulses 
concerned  in  the  reflex  acts  of  equilibration  that  are  asso- 
ciated with  the  cerebellar  centres.  These  paths  are  simi- 
lar to  those  already  found  in  the  vestibular  nerve  but  the 
peduncles  contain  efferent  as  well  as  afferent  paths.  The 
phenomena  observed  also  point  to  a  crossed  cerebellar  re- 
lation in  these  as  in  the  labyrinthine  paths  ^x\^  anatomical 


314  SEMICIRCULAR  CANALS 

investigations  lend  corroboration.  When  we  approach  the 
study  of  the  inferior  peduncle,  difficulties  are  encountered 
which  spring  from  the  complexity  of  its  structure  coupled 
with  the  inevitable  lack  of  uniformity  in  the  experimental 
findings. 

V.  Bechterew  ^^  found  that  section  of  the  inferior  pe- 
duncle in  any  part  of  its  course  from  the  olive  to  its  en- 
trance into  the  cerebellum,  as  well  as  injury  to  the  olive 
on  the  same  side  always  produced  rolling  movements  toward 
the  side  of  operation.  This  is  one  of  v.  Bechterew 's  chief 
reasons  for  maintaining  that  the  vestibular  nerve  is  mainly 
in  relation  with  the  homolateral  half  of  the  cerebellum. 
The  extreme  complexity  of  the  fibre  paths  in  the  inferior 
peduncle  render  it  difficult  to  deduce  reliable  conclusions 
from  lesion  of  this  structure.  The  proximity  of  Deiters' 
nucleus  and  of  the  vestibular  paths  to  and  from  it,  in- 
cluding vestibulo-olivary  paths  from  Deiters'  nucleus  to 
the  olive,  not  only  explain  the  phenomena,  but  turn  them 
to  account  as  strengthening  the  assumption  that  the  olives 
are,  in  part  at  least,  relay  stations  for  afferent  vestibular 
impulses  (vestibulo-olivo-cerebellar)  as  well  perhaps  as 
for  other  cerebellar  (afferent  and  efferent)  impulses. 

It  has  been  assumed  that  Helweg's  fasciculus  is  related 
to  the  inferior  olive.  Such  a  relationship  affords  oppor- 
tunity for  its  decussation  and  the  relaying  of  afferent  cere- 
bellar paths. 

Many  physiologists,  however  (Rolando,  ^'-^  Magendie,223 
and  others) ,  have  found  fairly  constant  and  uniform  results 
after  section  of  the  inferior  peduncle.  One  of  these  re- 
sults was  a  tendency  to  roll  to  the  side  of  the  lesion. 

Notwithstanding  the  diversity  of  opinions  as  to  the 
direction  in  which  the  animals  tend  to  roll  after  section 
of  the  various  peduncles,  or  after  removal  of  one-half  of 
the  cerebellum,  the  deviation  of  the  eyes  is  always  directed 
to  the  side  on  which  the  cerebellar  centres  and  their  re- 
lated afferent  and  efferent  paths  are  intact.  This  fact 
serves  as  a  guide  and  helps  us  to  avoid  those  errors  which 
must  inevitably  spring  from  confounding  phenomena  due 
to  irritation  with  those  due  to  destruction  and  automatic 
with  voluntary  compensatory  movements. 


CHAPTER  XXII 

ON    OCULAR    MOVEMENTS    AND   NYSTAGMUS 

Ferrier  and  Munk,  working  independently  of  each  other, 
first  located  the  centres  for  ocular  movements  in  the  frontal 
region  of  the  cerebral  hemispheres,  viz.,  in  the  posterior 
half  or  two-thirds  of  the  superior  and  middle  frontal  con- 
volutions. Stimulation  of  this  area  causes  movements  of 
the  head  and  eyes  toward  the  opposite  side. 

Horsley  and  Schafer^i^  confirmed  Ferrier's  results 
and  got  movements  from  a  more  extended  area.  Beevor 
and  Horsley  ^^  separated  the  area  for  movements  of  the 
head  from  that  for  movements  of  the  eyes  and  further 
differentiated  the  lateral  movements  of  the  eyes.  They 
found  that  turning  both  eyes  in  the  horizontal  plane 
toward  the  opposite  side  was  rare  as  a  primary  movement 
and  best  represented  in  the  convolutions  in  front  of  the 
paracentral  sulcus  and  to  a  less  extent  behind  it.  Move- 
ment of  both  eyes  to  the  opposite  side  and  upward  was 
found  to  be  rare  as  also  movements  of  both  eyes  to  the 
opposite  side  and  downward.  Limited  rotation  of  the 
eyes  sufficient  to  restore  the  direct  position  of  the  visual 
axes  was  frequently  observed.  Nystagmus  was  occasion- 
ally observed  on  stimulation  of  areas  in  front  of  the  pre- 
central  sulcus.  Schafer  ^^  discovered  in  the  occipital  region 
centres  for  ocular  movement  similar  to  those  found  by 
Ferrier  in  the  frontal  region.  Ferrier  ^  had,  however, 
already  obtained  movements  of  the  eyes  from  irritation  of 
the  occipital  areas,  but  considered  them  as  merely  associ- 
ated movements.  Sherrington  212  after  division  of  tbs 
third  and  fourth  cranial  nerves  upon  the  left  side,  observed 
conjugate  deviation  of  both  eyes  to  the  right  upon  excita- 
tion of  the  cortex  on  the  left  side,  viz.,  Ferrier's  ocular 
centre  in  the  frontal  region  and  Schafer 's  centre  in  the 
occipital  region.  Both  eyes  turned  to  the  right,  but  the 
left  only  went  as  far  as  the  middle  line. 

Sherrington  also  divided  the  sixth  nerve  on  the  left 

315 


316  SEMICIRCULAR   CANALS 

side  and  found  that  stimulation  of  the  frontal  cortex  of 
the  right  hemisphere  caused  the  right  eye  to  move  to  the 
left  sharply,  whilst  the  left  eye  did  not  move,  or  moved 
sluggishly  up  to  the  full  primary  position.  Sherrington 
concluded  that  the  straight  muscles  of  the  eye  can  be  in- 
hibited by  appropriate  excitement  of  certain  parts  of  the 
frontal,  and  still  better  of  the  occipital  cortex  on  the  side 
opposite  to  that  of  the  muscle.  He  found  that  this  inhi- 
bition takes  place  on  stimulation  of  the  corona  radiata 
and  occipital  radiations  after  removal  of  the  frontal  and 
occipital  cortex.  He  further  noted  that  on  severance  of 
the  third,  fourth,  and  sixth  nerves,  the  eyeball  assumed 
the  primary  position. 

Schafer  and  Mott^so  demonstrated  that  movements 
other  than  lateral  are  represented  in  the  cerebral  cortex. 
Ris ien- Russell, ^"^  working  independently,  also  demon- 
strated the  same  fact  in  an  interesting  series  of  experi- 
ments undertaken  especially  for  the  investigation  of  ocu- 
lar movements. 

In  monkeys,  after  division  of  the  internal  rectus  on  the 
side  of  cortical  stimulation,  and  of  the  external  rectus 
upon  the  opposite  side,  he  observed  up  and  down  move- 
ments of  the  eyeballs  on  irritation  of  the  frontal  ocular 
area.  By  practising  this  method  of  severance  of  certain 
muscles  the  following  movements  were  shown  to  be  related 
to  certain  areas  in  the  frontal  (and  presumably  also  in  the 
occipital)  cortex: 

1.  Direct  movement  of  both  eyes  downward;  centre 
just  above  horizontal  fissure  of  the  central  sulcus. 

2.  Direct  movement  of  both  eyes  upward;  centre  slight- 
ly above  and  in  front  of  the  preceding  area. 

3.  Movement  of  both  eyes  downward  and  to  the  oppo- 
site side;  centre  in  front  of  vertical  part  of  the  precentral 
sulcus  just  below  the  line  of  the  posterior  extremity  of  the 
horizontal  sulcus. 

4.  Movement  of  both  eyes  upward  and  to  the  opposite 
side;  centre  just  below  the  horizontal  fissure  of  the  precen- 
tral sulcus. 

5.  Movement  of  convergence ;  centre  not  constant,  but 
generally  in  front  of  centre  described  under  No.  3. 

0.  Direct  hiteral  movement  to  the  side  of  stimulation 
(excex^tional) . 


PHYSIOLOGY  317 

7.  Movement  upward  and  to  the  same  side  (excep- 
tional) . 

Russell  next  proceeded  to  practise  removal  of  the 
various  areas  in  the  frontal  cortex  corresponding  to  the 
location  of  the  centres  for  the  various  eye  movements. 
The  operations  caused  conjugate  deviation  of  the  eyes  to 
the  side  of  the  lesion.  In  time  the  deviation  was  corrected, 
but  returned  when  the  animal  was  anaesthetized  just  be- 
fore the  stage  of  surgical  anaesthesia,  whilst  the  corneal 
reflex  was  still  present.  With  the  advent  of  profound 
narcosis,  each  eyeball  moved  to  a  position  of  slight  out- 
ward deviation  which  is  the  normal  position  for  dogs  in 
deep  narcosis.  A  similar  divergence  of  the  eyes  with  in- 
dependent motions  was  observed  by  Mercier  and  Warner  ^^^ 
in  man  in  deep  coma  from  anaesthetics  or  other  cause.  In 
recovery  from  anaesthesia,  the  animal's  eyes  went  into 
conjugate  deviation  toward  the  side  of  the  lesion  and  re- 
mained thus  for  one  to  two  hours  after  restoration  to  con- 
sciousness. The  generally  accepted  view  as  to  the  causa- 
tion of  conjugate  deviation  after  removal  of  the  cerebral 
ocular  centres,  is  that  it  results  from  the  unopposed  action 
of  the  structures  upon  the  sound  side. 

Risien-Russell  attempts  to  explain  the  recovery  from 
deviation  after  operation.  There  are,  according  to  him, 
four  possibilities  to  account  for  the  phenomena: 

1.  The  remaining  parts  of  the  ocular  centres  take  on 
action. 

2.  Increased  supply  of  nervous  influence  from  the 
sound  hemisphere. 

3.  Cerebellar  compensation. 

4.  Diminished  output  of  energy  on  the  sound  side  to 
the  related  muscles. 

The  first  h}^3othesis  is  rejected  because  compensation 
occurs  even  where  the  whole  cortical  oculo-motor  area  of 
one  hemisphere  is  removed.  The  author  does  not  state 
whether  the  removal  included  the  occipital  as  well  as  the 
frontal  areas,  but  adds  that  ocular  movements  may  be  rep- 
resented in  lower  areas,  e.g.,  in  the  leg  and  arm  regions. 

The  second  hypothesis  is  rejected  as  unlikely  because 
movements  to  the  side  of  stimulation  are   exceptional. 

The  third  hypothesis  is  not  so  easily  dismissed  because 
of  the  findings  of  Ferrier  ^  and  Luciani,  ^  ^  The  former  found 


318  SEMICIRCULAR  CANALS 

on  irritation  of  certain  areas  of  the  cerebellum  that  the 
eyes  turned  to  that  side,  whilst  the  latter  found  on  abla- 
tion of  one  lateral  half  of  the  organ  that  the  eyes  turned 
to  the  opposite  side.  These  observations  show  that  each 
half  of  the  cerebellum  exerts  an  influence  upon  the  ocular 
movements  similar  to  that  exerted  by  the  opposite  cerebral 
hemisphere.  It  is  therefore  possible  that  the  cerebellum 
may  compensate  for  loss  of  the  cerebral  ocular  centres  and 
so  correct  the  conjugate  deviation. 

The  fourth  h}^othesis  seems  to  be  the  one  toward  which 
Russell  most  inclines.  The  amount  of  motor  energy  liber- 
ated by  any  centre  is  proportioned  to  the  resistance  to  be 
overcome.  After  destruction  of  one  area,  the  muscles  re- 
lated to  the  corresponding  area  on  the  opposite  side  have 
less  demand  put  upon  them  through  the  reflex  centres,  and 
their  related  centres  (on  the  sound  side)  gradually  accom- 
modate themselves  to  the  new  conditions,  i.e.,  become  less 
active. 

It  should  be  noted  that  this  is  a  purely  negative  sort 
of  recovery  at  the  expense  of  the  function  of  active  ocular 
movement.  Sherrington's  observation,  that  the  cerebral 
cortex  not  only  controls  the  straight  ocular  muscles  which 
turn  the  eyes  to  the  opposite  side,  but  actively  inhibits 
their  antagonists,  is  distinctly  opposed  to  this  view.  More- 
over, the  reappearance  under  anaesthesia  of  the  deviation 
which  had  been  recovered  from,  cannot  well  be  explained 
on  this  hypothesis.  The  same  objection  holds  for  cerebel- 
lar compensation.  If  the  cerebellar  mechanisms  be  in- 
cluded, the  most  plausible  explanation  is  afforded  by  hy- 
pothesis No.  1.  Thus  it  is  known  that  ocular  movements 
are  represented  in  the  frontal  and  in  the  occipital  areas, 
and  it  may  well  happen  that  eye  movements  are  repre- 
sented in  other  areas. 

The  compensation  for  conjugate  deviation  on  this 
hypothesis  therefore  takes  place  by  the  gradual  acquire- 
ment of  active  participation  of  other  areas  of  the  cerebral 
cortex  on  the  side  of  the  lesion.  Under  anaesthesia  the 
newly  acquired  functions  are  the  first  to  be  suspended,  thus 
permitting  the  reappearance  of  the  conjugate  deviation. 

When  complete  anaesthesia  supervenes  all  the  ocular 
centres  are  in  abeyance,  and  on  coming  out  of  the  anaes- 
thetic, the  centres  that  were  overcome  last  are  the  first  to 


PHYSIOLOGY  819 

recover,  causing  thereby  the  reappearance  of  conjugate  de- 
viation The  ocular  centres  of  both  cerebral  hemispheres 
do  not,  in  normal  dogs,  succumb  simultaneously  in  ether  or 
chloroform  narcosis  (Risien- Russell) .  This  fact  does  not 
necessarily  contravene  the  view  just  expressed  which  re- 
lates more  to  apes  and  the  higher  forms ;  for  in  the  dog 
ocular  and  other  movements  are  but  feebly  represented  in 
the  cerebral  cortex,  and  the  movements  so  represented  are 
probably  not  equally  represented  in  each  hemisphere. 
Thus  in  dogs  and  cats,  besides  the  lateral  movements,  the 
only  movements  represented  in  the  frontal  cortex  are  the 
upward  movements,  whilst  in  monkeys  all  sorts  of  move- 
ments are  represented  (Risien-Russell) .  This  clearly 
shows  the  relative  automaticity  that  obtains  in  ocular  and 
other  movements  in  the  dog  and  lower  forms  as  pointed 
out  by  Ferrier.  It  also  emphasizes  the  relative  importance 
of  the  mesencephalic,  cerebellar,  and  other  automatic  cen- 
tres in  these  lower  forms. 

It  has  long  been  known  that  the  cerebellum  influences 
ocular  movements. 

Saucerotte  222  (1769)  concluded  from  his  experiments 
that  the  eyes  receive  innervation  from  the  cerebellum. 

Magendie223  (1824)  described  the  position  of  the  eyes 
after  lesions  of  the  cerebellum  and  of  the  middle  peduncles. 
In  rabbits  he  found  on  section  of  one  middle  peduncle  the 
eye  on  the  same  side  turned  downward  and  forward  whilst 
that  of  the  opposite  side  turned  uuward  and  backward. 
(See  diagrams.) 

This  position  of  the  eyes  is  somewhat  similar  to  the 
position  observed  by  Biehl  ^°  on  section  of  the  right  ves- 
tibular nerve  in  the  sheep,  the  only  difference  being  that 
in  the  latter  the  position  of  the  left  eye  is  raised  and  that 
of  the  right  lowered.  When  the  corresponding  peduncle 
of  the  opposite  side  was  cut,  Magendie  found  that  the  oc- 
ular deviation  disappeared  and  the  eyes  reverted  to  the 
primary  position. 

Gratiolet  and  Leven224  (I860)  incised  the  cerebellum 
vertically  through  the  centre  of  one  lateral  lobe  and  ob- 
served that  the  eye  on  the  same  side  turned  downward  and 
backward,  whilst  that  on  the  other  side  turned  upward 
and   forward.      Leven   and    011ivier225    passed    needles 


820  BEMICIRCULAR  CANALS 

through  the  skulls  of  guinea-pigs  into  the  cerebellum,  and 
observed  strabismus.  Renzi  ^26  (1864)  concluded  that  in 
fishes  the  cerebellum  influenced  vision  by  regulation  of 
the  co-ordinated  voluntary  movements  of  the  eyeballs. 
Weir-Mitchell  ^2  (1869)  observed  that  most  deep  lesions 
of  the  cerebellum  produced  strabismus.  Ferrier  ^  found 
that  irritation  of  areas  of  the  cerebellum  in  and  about  the 
vermis  caused  various  movements  of  the  eyes,  the  general 
direction  being  toward  the  side  of  irritation.  He  also  ob- 
served contraction  of  the  pupils,  especially  on  the  homo- 
lateral side,  bulging  of  the  eyeballs,  and  movements  of  the 
limbs,  etc.,  upon  the  side  of  irritation.  Luciani  ^^  (1891) 
found  on  extirpation  of  one-half  of  the  cerebellum  that  the 
eyes  turn  to  the  opposite  side.  He  also  observed  strabis- 
mus and  nystagmus  after  removal  of  different  parts  of  the 
cerebellum.  Risien-Russell  on  reuioval  of  one  lateral  lobe 
of  the  cerebellum  in  dogs  and  cats  observed  a  skew  devi- 
ation of  the  eyes,  the  eye  on  the  side  of  the  lesion  turning 
upward  and  forward,  whilst  the  opposite  eye  turned  down- 
ward and  backward.  When  the  effects  of  the  anaesthetic 
had  passed  off,  the  eye  on  the  side  of  the  cerebellar  lesion 
went  back  to  the  primary  position,  whilst  the  eye  on  the 
opposite  side  maintained  its  abnormal  position  for  sev- 
eral days.  Removal  of  both  lateral  lobes,  leaving  the 
middle  lobe  intact,  caused  both  eyeballs  to  rotate  down- 
ward and  to  a  variable  extent  outward.  Excision  of  half 
the  posterior  part  of  the  middle  lobe  caused  the  eye  of  the 
same  side  to  rotate  downward  and  outward.  Excision  of 
the  whole  of  the  posterior  part  of  the  middle  lobe  caused 
both  eyes  to  turn  downward  and  slightly  outward.  Total 
ablation  of  the  cerebellum  caused  a  variable  amount  of 
downward  rotation  of  both  eyeballs.  All  these  ocular  de- 
viations were  recovered  from  in  a  variable  length  of  time. 
After  recovery  the  deviations  were  re-established  during 
narcosis. 

Two  forms  of  nystagmus  were  observed: 
A  spontaneous  form  which  was  of  a  definite  direc- 
tion irrespective  of  voluntary  ocular  movements;  and 
nystagmoid  jerks  which  occurred  only  wh(3n  the  globes 
were  moved  voluntarily,  the  direction  of  the  jerks  being 
the  same  as  that  in  which  the  glo})es  were  moved. 

Ablation  of  one  lateral  lobe  caused  nystagmus  which 


PHYSIOLOGY  821 

was  of  more  or  less  constant  occurrence,  and  which  lasted 
for  a  variable  time  after  the  operation  at  times  only  for 
a  day  or  two.  The  nystagmus  was  always  lateral  and 
consisted  of  slow  jerks  toward  the  side  of  the  lesion.  The 
jerks  were  more  marked  in  the  eye  on  the  sound  side. 

Removal  of  both  lateral  lobes  caused  nystagmus  of  up- 
ward direction  with  a  tendency  of  the  upper  segment  of 
each  globe  to  rotate  from  within  outward  at  first.  This 
spontaneous  nystagmus  was  replaced  by  nystagmoid  move- 
ments which  occurred  only  when  the  eyes  were  moved. 
The  direction  of  these  nystagmoid  movements  was  that  in 
which  the  eyes  were  moved.  In  the  course  of  two  or 
three  days  all  nystagmus  had  disappeared. 

Extirpation  of  one  lateral  half  of  the  posterior  part  of 
the  middle  lobe  caused  nystagmus  of  both  globes.  The 
jerks  were  toward  the  opposite  side  and  slightly  upward. 

Ablation  of  the  whole  posterior  part  of  middle  lobe 
caused  vertical  nystagmus  with  occasional  irregular  rota- 
tory movements. 

Ablation  of  the  whole  cerebellum  did  not  cause  spon- 
taneous nystagmus,  but  there  appeared  nystagmoid  jerks 
of  both  globes  in  the  direction  of  the  voluntary  ocular 
movements.  After  recovery  from  the  nystagmus  following 
cerebellar  lesion,  ether  or  chloroform  narcosis  caused  a 
reappearance  of  the  nystagmus  just  as  the  globes  were 
about  to  turn  to  one  side  or  the  other.  It  ceased  as  the 
anaesthesia  deepened  and  the  abnormal  (normal  for  nar- 
cosis) position  of  the  eyes  was  established.  This  was 
seen  several  months  after  ablation  of  one  lateral  lobe. 

By  way  of  control,  experiments  were  made  by:  1,  ex- 
tirpating the  labyrinth  on  one  side;  2,  by  intra-cranial 
section  of  the  eighth  nerve;  and  3,  by  chemical  irritation 
of  the  eighth  nerve  on  one  side.  All  these  procedures,  ac- 
cording to  Risien-Russell,  were  followed  by  similar  results, 
viz. ,  rotation  of  the  eye  upon  the  side  of  the  lesion  down- 
ward. There  was  doubt  as  to  whether  there  was  also  an 
additional  displacement  outward  as  described  by  v.  Bech- 
terew,  or  inward,  sometimes  the  one  and  sometimes  the 
other  being  observed. 

The  eye  on  the  sound  side  was  turned  inward  but  with- 
out the  upward  rotation  described  by  v.  Bechterew. 

Nystagmus  was  always  marked  just  after  the  opera- 


322  SEMICIRCULAR   CANALS 

tion,  the  direction  being  upward  with  a  varying  amount 
of  inward  element  in  the  eye  on  the  side  of  the  lesion,  and 
lateral,  with  the  jerks  outward,  in  the  eye  of  the  sound  side. 
It  was  noted  that  two  or  three  hours  after  the  operation 
there  might  appear  rotary  nystagmus  of  both  eyes  in 
which  the  upper  segment  of  the  eye  on  the  side  of  opera- 
tion rotated  inward,  whilst  that  of  the  opposite  eye  rota- 
ted outward. 

Ablation  of  the  frontal  ocular  area  of  one  hemisphere, 
followed  later  by  extirpation  of  the  opposite  lateral  lobe 
of  the  cerebellum.    See  diagrams  (pp.  329,  380).    Stages: 

1.  In  narcosis  before  operation  the  eyes  were  turned 
to  the  left. 

2.  Removal  of  part  of  ocular  area  of  the  right  hemis- 
phere caused  both  eyes  to  turn  to  the  right. 

3.  In  a  few  days  the  eyes  had  resumed  their  normal 
position. 

4.  Removal  of  left  lateral  lobe  of  cerebellum  caused 
the  right  eye  to  turn  to  the  right  with  a  downw^ard  incli- 
nation.    The  left  eye  was  unaffected. 

Hence  removal  of  one  lateral  lobe  of  cerebellum  in  an 
animal  deprived  of  part  of  its  frontal  ocular  area  of  the 
opposite  cerebral  hemisphere  has  the  same  result  as  the 
same  operation  done  upon  an  animal  with  the  cerebral 
ocular  areas  intact.  Ablation  of  part  of  the  eye  area  of 
one  hemisphere  was  followed  later  by  extirpation  of  the 
lateral  cerebellar  lobe  of  the  same  side.  The  effect  of  the 
second  operation  was  to  cause  the  eye  on  the  sound  side 
to  turn  outward  slightly,  certainly  to  a  much  less  extent 
than  a  similar  operation  on  dogs  with  intact  cerebral 
hemispheres. 

This  experiment  indicates  clearly  the  functional  de- 
pendence of  the  lateral  cerebellar  lobe  upon  the  related  cor- 
tical area  of  the  oppcjsite  cerebral  hemisphere.  Assuming 
that  compensation  after  the  first  operation  had  taken  place 
by  the  active  intervention  of  the  other  ocular  centres  in  the 
right  liemisphere,  it  may  also  be  assumed  that  sufficient 
time  had  not  elapsed  for  the  new  afferent  cerebro-cerebellar 
paths  to  funrtion  ])iT)perly.  The  effect  of  removal  of  the 
cere))ral  ocular  area  on  the  right  side  may  properly  be 
compared  with  the  effect  of  section  of  the  right  vestibular 
nerve,  in  that  it  withdraws  the  afferent  cerebellar  tonus 


PHYSIOLOGY  823 

impulses  from  the  left  half  of  the  cerebellum,  so  that  when 
the  antagonistic  centres  in  the  right  half  of  the  cerebellum 
are  removed,  little  or  no  deviation  of  the  eyes  occurred. 
The  fact  that  there  was  some  deviation  of  the  left  eye 
toward  the  left,  seems  to  prove  that  this  latter  was  not 
due  to  the  inequality  of  direct  cortical  innervation  to  the 
ocular  muscles,  inasmuch  as  the  deviation  due  to  the  first 
operation  had  already  been  compensated.  On  the  other 
hand  it  might  be  said  that  this  compensation  was  effected 
through  overactivity  of  the  left,  or  underactivity  of  the 
right  half  of  the  cerebellum.  The  reappearance  of  the 
ocular  deviations  in  narcosis  and  other  considerations,  e.g. , 
the  slight  extent  of  the  deviation  of  the  left  eye  after  the 
second  operation,  render  this  extremely  improbable. 

We  are  therefore  driven  to  the  conclusion  that  the  de- 
viation that  occurred  after  the  second  operation  was  the 
result  of  afferent  cerebro-cerebellar  tonus  impulses  reaching 
the  left  half  of  the  cerebellum  from  the  ocular  centres  in 
the  right  hemisphere  that  had  not  been  interfered  with  in 
the  first  operation.  The  insignificance  of  the  deviation 
is  accounted  for  by  the  fact  that  the  chief  ocular  (frontal) 
area  had  been  removed  upon  the  right  side,  thereby  cut- 
ting off  most  of  the  normal  afferent  cerebro-cerebellar  im- 
pulses to  the  left  half  of  the  cerebellum  for  which  of  course 
partial  compensation  had  been  made.  When,  therefore, 
the  right  lateral  lobe  was  removed,  the  eyes  practically  re- 
mained in  the  primary  position  just  as  they  do  in  section 
of  both  vestibular  nerves  or  section  of  all  the  nerves  to  the 
ocular  muscles.  In  other  words  removal  of  areas  of  cere- 
bral cortex  upon  one  side  tends  to  counterbalance  the 
effects  of  removal  of  the  lateral  lobe  of  the  cerebellum  upon 
the  same  side,  or  of  section  of  the  vestibular  nerve  on  the 
opposite  side.  Extirpation  of  one  lateral  lobe  of  the  cere- 
bellum, followed  later,  by  removal  of  part  of  the  frontal 
eye-area  of  the  opposite  cerebral  hemisphere  gave  results 
like  those  observed  when  the  cerebral  ocular  area  was  re- 
moved first  and  then  the  opposite  lateral  lobe  of  the  cere- 
bellum. 

Extirpation  of  one  lateral  lobe  of  the  cerebellum  fol- 
lowed later  by  removal  of  part  of  the  frontal  eye-area  in 
the  cerebral  hemisphere  of  the  same  side  gave  results,  like 
those  observed  when  the  cerebral  eye-area  was  first  removed 


824  SEMICIRCULAR  CANALS 

and  then  the  lateral  lobe  of  the  cerebellum  on  the  same 
side. 

Removal  of  part  of  the  frontal  eye-area  of  one  cerebral 
hemisphere  and  extirpation  on  the  same  side  of  the  lateral 
lobe  of  the  cerebellum  in  one  operation  caused  the  eye  on 
the  side  of  operation  to  turn  toward  the  side  of  the  le- 
sions. The  eye  on  the  sound  side  was  not  appreciably 
affected. 

These  experiments  seem  to  indicate  that  in  the  conju- 
gate lateral  movements  of  the  eyes  in  the  dog  and  cat  the 
contra-lateral  eye  in  its  outward  movement  (external  rec- 
tus) is  more  strongly  represented  in  the  cerebral  cortex 
than  the  homo-lateral  eye  in  its  associated  movement  (in- 
ternal rectus) .  Similarly  in  the  cerebellum  the  outward 
movement  of  the  homo-lateral  eye  (external  rectus)  is 
more  strongly  represented  than  the  corresponding  associ- 
ated movement  of  the  contra-lateral  eye  (internal  rectus). 

The  deviations  and  strabismus  that  follow  ablations  of 
portions  of  the  cerebellum  are  usually  attributed  to  irrita- 
tion of  the  remaining  fibres  or  centres.  But  Risien-Russell 
considers  them  as  paralytic  phenomena  because,  after  com- 
pensation, the  deviation  reappears  in  ether  or  chloroform 
narcosis,  and  no  mere  irritative  effect  could  behave  in  this 
way.  The  results  of  Ferrier  and  of  Luciani  support  this 
view.  The  question  arises  as  to  whether  the  effects  of  re- 
moval of  portions  of  the  cerebellum  are  due  to  the  with- 
drawal of  some  direct  influence  of  the  cerebellum  upon  the 
muscles,  or  to  an  indirect  effect  upon  the  muscles  brought 
about  through  the  agency  of  the  cerebral  hemispheres  of 
the  same,  or  of  the  opposite  side,  viz. ,  by  the  removal  from 
the  cerebellum  of  some  influence  originating  normally  in 
the  cells  of  the  cerebral  cortex.  Risien-Russell  himself 
lias  shown  that  each  half  of  the  cerebellum  exerts  impor- 
tant influences  upon  the  cortical  cells  of  the  opposite 
cerebral  hemisphere,  and  that  unilateral  lesions  of  the 
cerebellum  induce  inequality  of  excitability  in  the  two 
cerebral  hemispheres,  the  hemisphere  on  the  side  opposite 
to  that  of  the  cerebellar  lesion  being  the  more  excitable,  al- 
though Luciani  found  increased  excitability  in  some  parts 
and  depression  in  other  parts.  Risien-Russell  believes 
the  abnormal  position  of  the  eyes  after  ablation  of  parts 
of  the  cerebellum  is  due  to  withdrawal  of  cerebellar  influ- 


PHYSIOLOGY  825 

ence  exerted  directly  upon  the  ocular  muscles  and  not  in- 
directly by  way  of  the  cerebral  cortex.  He  bases  his  opin- 
ion upon  the  fact  that  after  removal  of  part  of  one  cerebral 
eye-area,  ablation  of  the  lateral  lobe  of  the  cerebellum  upon 
the  opposite  side  causes  exactly  the  same  amount  of  devia- 
tion that  is  seen  upon  removal  of  one  lateral  lobe  of  the 
cerebellum  with  the  cerebral  areas  of  the  opposite  side  in- 
tact. He  believes  that  spontaneous  nystagmus  is  an  irri- 
tation phenomenon  reflexly  induced,  whilst  the  nystag- 
moid movements  evoked  by  voluntary  movements  of  the 
eyeballs  is  a  paralytic  phenomenon  due  to  weakness  of  the 
muscles  producing  movement  of  the  eyes  in  any  one  direc- 
tion or  to  weakness  of  the  antagonists  of  those  muscles. 

Beevor  and  Horsley^^  observed  that  nystagmus  only 
infrequently  occurred  upon  irritation  of  the  cerebral  cortex 
and  then  only  in  very  limited  areas  anterior  to  the  frontal 
ocular  areas.  In  operations  upon  the  cerebellum  or  upon 
its  peduncles,  Ferrier^  observed  that  violent  irregular  nys- 
tagmus is  always  present  during  the  manipulations  and  it 
is  only  some  time  after  the  eyes  have  quieted  down  that 
the  nystagmus  can  be  properly  studied. 

The  spontaneous  nystagmus  which  accompanies  active 
or  passive  rotation  is  a  highly  co-ordinated  act  intended 
to  facilitate  the  visual  fixation  of  passing  objects.  Hence 
the  short,  rapid  jerks  which  enable  us  to  see  the  moving 
objects  continuously  without  suspension  of  vision  even 
during  the  adjustments  of  the  eyes.  Such  adjustments  of 
the  eyes  are  not  possible  where  the  centres  for  the  balanced 
cerebellar  mechanisms  are  removed  or  impaired.  We 
must  conclude,  therefore,  that  the  spontaneous  nystagmus 
observed  upon  removal  of  parts  of  the  cerebellum  is  due 
to  enhanced  irritability  relative  or  absolute  of  fibres  or 
centres  that  are  left  intact.  Thus  in  Risien-Russell's  ex- 
periments, ablation  of  one  lateral  lobe  caused  lateral  nys- 
tagmus with  slow  jerks  toward  the  side  of  the  lesion.  As 
the  centres  for  the  lateral  movements  of  the  eyes  are  located 
just  to  the  left  and  right  of  the  pyramid  in  the  dog,  and 
in  the  right  and  left  curve  of  the  median  lobe  in  the  cat 
(Ferrier)  it  seems  most  probable  that  the  operation  for  re- 
moval of  the  lateral  lobe  simply  impaired  somewhat  the 
centres  for  one  limb  of  the  balanced  mechanisms,  thereby 
causing  relatively  increased  tonus  in  the  corresponding 


32a  SEMICIRCULAR   CANALS 

mechanisms  of  the  opposite  side  and  spontaneous  nystag- 
mus toward  the  side  of  the  lesion. 

Removal  of  both  lateral  lobes  causes  upward  nystagmus 
with  a  tendency  of  the  upper  segment  of  each  eye  to  rotate 
from  within  outward  at  first.  This  spontaneous  nystag- 
mus was  replaced  by  nystagmoid  movements  which  oc- 
curred only  when  the  eyes  were  moved.  The  direction  of 
these  movements  was  that  of  the  voluntary  movements  of 
the  eyes. 

By  means  of  aural  irrigations  we  have  shown  that  bi- 
lateral irritation  or  depression  of  the  labyrinthine  receptors 
may  be  accompanied  by  vertical  nystagmus.  In  other 
words  equal  irritation  of  corresponding  cerebellar  centres 
related  to  the  horizontal  semicircular  canals  was  without 
effect  in  causing  the  usual  lateral  horizontal  nystagnuis 
which  accompanies  unilateral  aural  irrigations.  We  may 
therefore  assume  that  in  removal  of  both  lateral  lobes  the 
centres  for  the  lateral  movements  of  the  eyes  on  either  side 
of  the  pyramid  were  equally  affected,  directly  or  indirectly. 
The  possibility  of  such  an  occurrence  is  at  once  apparent 
when  it  is  remembered  that  the  centre  for  the  vertical 
downward  movement  of  the  eyes  in  apes  is  in  the  posterior 
extremity  of  the  vermiforai  process,  whilst  the  centre  for 
the  corresponding  upward  movements  is  in  the  anterior 
extremity  of  the  vermiform  process.  Bilateral  irritation 
of  the  centres  located  in  the  lateral  lobes  (semilunar  lob- 
ules) would  account  for  the  outward  rotation  of  the  eye- 
balls just  after  the  operation. 

Ablation  of  one  lateral  half  of  the  posterior  part  of  the 
middle  lobe  caused  lateral  nystagmus  to  the  left  and  slightly 
upward  whilst  ablation  of  the  whole  posterior  part  of  the 
middle  lobe  caused  vertical  nystagmus  of  an  upward  direc- 
tion which  is  readily  explicable  when  the  functions  of  the 
centres  located  in  that  portion  of  the  cerebellum  are  re- 
membered.    See  Chapter  XXII. 

Ablation  of  the  whole  cerebellum  causes  no  spontaneous 
nystagmus.  There  occur,  however,  in  both  eyes  nystag- 
moid movements  which  follow  the  voluntary  ocular  move- 
ments. The  results  of  this  last  experiment  seem  to  sup- 
port the  view  expressed  in  a  previous  chapter  that  removal 
or  serious  injury  of  any  of  the  cerebellar  centres  causes, 
not  spontaneous  nystagmus,  but  nystagmoid  movements 


PHYSIOLOGY  327 

and  deviations.  The  significance  of  these  movements 
should  therefore  be  remembered  in  the  diagnosis  of  cere- 
bellar lesions.  After  compensation  has  been  made  for  the 
nystagmus  following  cerebellar  lesions  the  reappearance  of 
the  nystagmus  under  ether  narcosis  does  not  necessarily 
imply  that  the  nystagmus  was  originally  a  paralytic  phe- 
nomenon. Indeed  the  facts  seem  to  justify  the  opposite 
conclusion,  for  such  a  highly  co-ordinated  act  as  physio- 
logical nystagmus  necessarily  implies  intact  mechanisms 
rather  than  mechanisms  that  have  been  more  or  less  com- 
pletely destroyed.  However,  as  the  centres  in  one  portion 
of  the  cerebellum  are  set  up  against  the  centres  in  another 
portion  (balanced  mechanisms)  it  can  be  readily  under- 
stood how  impairment,  destruction,  or  irritation  of  the 
centres  in  any  one  area  may  disturb  the  relations  of  the 
balanced  mechanisms  and  so  cause  nystagmus.  In  these 
instances  if  the  lesion  of  the  cerebellum  be  a  fairly  gross 
one  the  ocular  movements  will  be  of  the  nystagmoid 
variety.  With  a  lesser  lesion  they  may  resemble  the 
movements  of  true  spontaneous  nystagmus,  but  some 
irregularity  will  be  exhibited,  especially  in  the  reactions 
to  aural  irrigations,  rotations,  or  galvanism. 

In  accounting  for  the  discrepancies  between  the  results 
of  various  physiologists  it  should  be  remembered  that  it 
is  a  matter  of  some  difficulty  to  determine  the  direction 
of  nystagmus  in  animals,  and  that  in  experiments  upon 
the  exceedingly  sensitive  labyrinth  "retardation  phe- 
nomena" may  supervene,  making  it  appear  that  similar 
operations  give  contradictory  results.  The  rapidity  of 
the  short  elements  in  nystagmus  is  so  great  that  during 
their  execution  vision  is  impossible.  For  the  same  reason 
direct  observation  of  these  movements  in  the  eyes  is  often 
an  impossibility.  Nystagmus  is  more  conveniently  studied 
in  the  human  subject  w^bere  the  findings  can  be  corrobor- 
ated by  the  subjective  sensations  (i.e.,  sense  of  rotation, 
apparent  movement  of  external  objects)  and  above  all  by 
the  aid  of  the  ophthalmoscope. 

The  discrepancies  between  the  observations  of  Risien- 
Russell  and  those  of  Luciani  after  ablation  of  one  "lateral 
lobe"  and  "one  half"  of  the  cerebellum  respectively  can 
be  accounted  for  by  the  fact  that  Luciani 's  operation  re- 
moved the  whole  half  of  the  cerebellum,  including  ocular 


328  SEMICIRCULAR   CANALS 

centres  in  and  about  one  side  of  the  median  lobe  which  of 
course  escaped  in  Risien-Russell's  operation. 

These  experiments  demonstrate  conclusively  the  exist- 
ence of  both  cerebral  and  cerebellar  balanced  mechanisms 
for  the  control  of  ocular  movements.  In  the  dog  and  cat 
the  only  movements  that  seem  to  be  represented  in  the 
frontal  ocular  areas  are  the  lateral  and  upward  vertical 
(Risien-Russell)  whilst  in  the  apes  and  presumably  in 
man,  the  various  other  movements  are  represented.  The 
cerebral  mechanisms  are  represented  in  paths  that  lead  from 
each  frontal  ocular  area  through  the  corona  radiata,  with 
or  without  interruption  in  the  basal  ganglia,  to  the  oculo- 
motor nuclei  of  the  opposite  side.  The  centres  in  each 
frontal  area  control  the  muscles  that  move  the  eyeballs  in 
a  cei'tain  direction  and  at  the  same  time  inhibit  the  antag- 
onistic muscles  which  move  the  eyeball  in  the  opposite 
direction.  These  mechanisms  are  of  course  under  volun- 
tary control,  but  perhaps  owing  partly  to  their  relation  to 
the  cerebellar  mechanisms  the  ordinary  movements  of  the 
eyeballs  are  mainly  executed  in  a  reflex  manner. 


DIAGRAM  TO  SHOW  THE  EFFECTS  OF  THE  VARI- 
OUS OPERATIONS  UPON  THE  CEREBELLUM, 
WITH  THE  RESULTS  OF  SOME  OTHER  OPERA- 
TIONS  FOR   COMPARISON. 

1.  Section  of   left  middle    peduncle    in   rabbit       ftl  )     (m  ) 
(Magendie).  ^     ^i^ 

®® 

4.  Incision  of  left  lateral  lobe  (Gratiolet   and        C  w)    C ^ 

Leven).  ^^-^    ^^^ 

5.  Ablation  of  left  half  of  cerebellum  (Luciani). 


2.  Section  of  right  vestibular  nerve   in   sheep 

(Biehl). 

3.  Section  of  both  middle  peduncles  (Magendie) . 


Removal  of  left  lateral  lobe  ;  just  after  oper- 
ation (Risien-Russell). 

Ditto  when  effects  of  anesthesia  have  passed 
off  (Risien-Russell). 


8.  Removal  of  both  lateral  lobes ;   middle  lobe 

intact  (Risien-Russell). 

9.  Excision  of  left  half  of  posterior  part  of 

middle  lobe  (Risien-Russell). 

10.  Excision  of  whole  posterior  part  of  middle 

lobe  (Risien-Russell). 

11.  Total    ablation  of   cerebellum   (Risien-Rus- 

sell).  __        _^ 

12.  Ablation  of  left  lateral   lobe.     Nystagmus     "/ — \  ~  /T\ 

(slow)  to  left  (Risien-Russell). 

13.  Removal  of  both  lateral  lobes.     Nystagmus     ^f^^  /\ 

at    first ;    later  nystagmoid  movements 
(Risien-Russell). 

14.  Extirpation  of  left  half  of  posterior  part  of 

middle   lobe.     Nystagmus    (Risien-Rus- 
sell). 


©0 

(s)(i) 


15.  Ablation  of  whole  posterior  half  of  middle 

lobe.     Nystagmus  (Risien-Russell). 

16.  Section  of  eighth  nerve  of  right  side  (Risien- 
Russell). 


©T® 
Q  €) 

17.  Section  of  eighth  nerve  of  right  side  (Bech-      U^j    iW) 
terew).  -?~d^jS->l>, 

same,  two  or  tnree  nours  alter  operation     '/^^vV 
(Risien-Russell).  \^} 


18.  Nystagmus  just  after  section  of  eighth  nerve 
(right)  (Risien-Russell). 


19.  The  same,  two  or  three  hours  after  operation 

329 


DIAGRAM  TO  SHOW  THE  OCULAR  DEVIATIONS 
FOLLOWING  REMOVAL  OF  PARTS  OF  THE  OCU- 
LAR CEREBRAL  AREAS  AND  OF  PORTIONS  OF 
THE   CEREBELLUM. 

a.  Narcosis ;  eyes  before  operation.  Cm     (m 

b.  Removal  of  frontal  ocular  area  of  right  hem- 

isphere. 

c.  Lapse  of  few  days ;  eyes  in  normal  position.  i#)     uf^S 

d.  Removal  of  left  lateral  lobe  of  cerebellum. 


0  © 
®  0 
©  0 


a.  Narcosis;  eyes  before  operation.  Cm  TlW 

b.  Removal  of  frontal  ocular  area  of  right  hem-  /^\  /C\ 

isphere.  ^  ^ 

c.  Lapse  of  few  days ;  eyes  in  normal  position.  Qfn  (9j 

d.  Excision  of  right  lateral  lobe  of  cerebellum.  ^4|^  /^ 


a.  Narcosis  ;  eyes  before  operation.  Cm     Cm 

€)  0 
0  0 
00 


b.  Removal  of  left  lateral  lobe  of  cerebellum. 

c.  Lapse  of  some  days ;  eyes  in  normal  position. 

d.  Removal  of  frontal  ocular  area  of  right  hem- 

isphere. 


a.  Narcosis ;  eyes  before  operation. 

b.  Extirpation  of  left  lateral  lobe  of  cerebellum. 

c.  Lapse  of  few  days ;  eyes  in  normal  position. 

d.  Removal  of  frontal  ocular  area  of  left  hem- 

isphere. 


0  0 

0  0 
0  Q 


CHAPTER  XXIII 

ON  THE  OCCURRENCE  OF  NYSTAGMUS 

Theoretically  nystagmus  can  be  produced  only  by  in- 
terference with  the  co-ordinating  mechanisms  of  ocular 
movement.  As  nystagmus  is  a  highly  co-ordinated  move- 
ment effected  by  alternating  reflexes  in  which  inhibition 
plays  such  an  important  role,  interference  with  the  oculo- 
motor nerves  as  in  the  case  of  the  spinal  motor  neurones 
of  which  they  are  the  analogues,  does  not  cause  true  nys- 
tagmus but  paralysis  of  ocular  movement.  And  similarly, 
since,  in  the  two  sets  of  reflex  arcs  involved  in  nystagmus, 
interference  with  the  efferent  arcs  of  the  final  common  path 
(ultimate  neurone)  upon  one  side  of  the  body  would  not 
cause  nystagmus,  but  rather  absence  of  the  related  element 
of  the  nystagmus,  or  in  other  words  a  paralysis.  For 
these  reasons,  and  because  inhibition  is  so  frequently  de- 
pendent on  stimuli  originating  in  the  receptive  field  and 
transmitted  by  way  of  the  afferent  neurones  (Sherrington^^) 
we  must  look  to  the  afferent  arcs  or  co-ordinating  centres 
in  the  cerebellum  as  the  chief  site  of  interference  in  the 
causation  of  nystagmus. 

As  these  afferent  arcs  originate  in  the  labyrinthine  and 
retinal  receptors,  and  possibly  in  portions  of  the  cerebral 
cortex,  it  is  evident  lesions  of  any  extent  within  the  cranial 
cavity  interfering  with  the  afferent  paths  as  well  as  lesions 
of  very  limited  extent,  e.g.,  a  tiny  patch  of  sclerosis,  a 
small  exudate,  or  a  tiny  thrombus  or  embolus  in  the  cere- 
bellar co-ordinating  centres,  may  cause  nystagmus.  Hence 
nystagmus  is  set  down  in  text-books  as  one  of  the  gen- 
eral symptoms  of  disturbed  cerebral  function.  The  ques- 
tion arises,  however,  as  to  why  nystagmus  is  so  seldom 
produced  by  irritation  or  ablation  of  the  cerebral  cortex. 
The  answer  is  that  such  nystagmus  is  occasionally  seen 
(Beevor  and  Horsley  *°)  although  ordinarily  it  is  inhibited 

331 


832  SEMICIRCULAR   CANALS 

by  the  conspicuous  ocular  deviations  that  accompany  irri- 
tation and  ablation  of  the  cerebral  ocular  centres.  It  will 
be  noted  that  these  ocular  deviations  are  of  such  direction 
as  would  inhibit  the  nystagmus  that  should  accompany 
such  a  lesion,  i.e.,  that  they  are  in  the  direction  opposite 
to  that  of  the  short  elements. 

Destruction  of  the  cerebellum  or  lesions  destroying  or 
causing  suspension  of  function  of  the  ocular  co-ordinating 
centres  to  any  great  extent  causes,  not  nystagmus,  but 
nystagmoid  movements  in  which  the  sharp  differentiation 
of  the  short  and  long  elements  is  wanting. 

Visible  nystagmus  most  frequently  results  from  lesion 
or  interference  with  the  ocular  or  labyrinthine  mechanisms. 
Milder  grades,  however,  readily  detected  by  means  of  the 
ophthalmoscope,  are  of  very  frequent  occurrence  and  are 
usually  overlooked.  These  milder  forms  of  nystagmus 
are  generally  caused  by  irritation  of  the  cerebral  cortex  by 
toxines  of  various  kinds  circulating  in  the  blood  since  the 
cortical  centres  seem  to  be  more  readily  affected  by  various 
poisons  than  the  purely  reflex  centres,  cerebellar  or  other. 
On  this  ground  may  be  explained  the  recurrence  of  ocular 
deviations  in  the  experiments  of  Risien-Russell.^'' 

These  mild  ophthalmoscopic  forms  of  nystagmus  are 
important  features  in  minor  forms  of  disturbances  of  equi- 
librium. There  are  good  reasons  for  believing  that  vertigo, 
with  its  attendant  subjective  distress,  is  seldom  or  never 
experienced  in  the  absence  of  nystagmus,  although  it  has 
been  recorded  that  some  persons  suffered  from  vertigo  even 
after  removal  of  both  eyeballs.  The  close  relation  between 
vertigo  and  vomiting  makes  it  probable  that  the  vertigo 
of  gastric  disorders  may  not  wholly  originate  in  toxemia 
of  the  cerebral  centres,  but  may  be  mediated  through  affer- 
ent impulses  initiated  by  direct  irritation  of  the  recep- 
tors in  the  alimentary  canal. 

Miner's  nystagmus  seems  to  be  caused  by  the  strained 
and  unusual  position  of  the  head,  whereby  certain  sets  of 
vestibulo-  and  oculo-cerebellar  mechanisms  are  in  constant 
and  prolonged  use,  so  that  exhaustion  of  the  neurones  in- 
volved ensues  with  a  condition  of  localized  neurasthenia 
similar  in  every  respect  to  an  occupation  neurosis.  When 
the  subject  resumes  his  natural  position  the  weakened  por- 
tion of  the  oculo-  or  yestibulo-cerebellar  mechanisms  is  no 


PHYSIOLOGY  333 

longer  capable  of  offering  the  adequate  counteraction  to 
the  opposing  mechanisms  to  secure  a  proper  balance  of 
reflex  tonus  innervation.  The  result  is  nystagmus.  Pos- 
sibly a  similar  explanation,  i.e.,  neurasthenia  of  certain 
sets  of  vestibulo-cerebellar  mechanisms  holds  for  Gertier's 
disease  with  its  attacks  of  vertigo,  paralysis  (paresis)  of 
the  neck  muscles  allowing  the  head  to  fall  forward,  etc. 
This  disease  occurs  frequently  in  France,  Switzerland,  and 
Japan,  and  is  especially  noted  in  those  who  are  much 
fatigued  and  neurotic  or  emotional,  and  in  those  working 
in  a  lowered  position  (Starr  ^26).  The  author  has  seen 
nystagmus  occur  in  an  infant  of  neurotic  heredity  upon 
the  eruption  of  each  of  the  first  four  teeth.  The  child  was 
in  fair  general  health,  and  fairly  well  up  to  the  average 
in  intelligence  and  development  for  children  of  her  age. 
There  was  a  distinct  tendency  for  the  tooth  on  one 
side  to  appear  long  before  the  corresponding  tooth  on  the 
other  side.  With  the  eruption  of  the  left,  lower,  central 
incisor,  there  was  a  deviation  of  the  head  toward  the  right, 
and  a  nystagmus  of  mixed  type  with  a  general  direction 
toward  the  left.  The  child  on  looking  at  any  object,  held 
in  a  fixed  position  upon  her  left,  lowered  the  head  so  that 
she  could  look  at  it  out  of  the  right  corners  of  her  eyes,  a 
position  in  w^hich  the  nystagmus  was  at  a  minimum.  The 
explanation  of  the  teething  nystagmus  is  afforded  by  the 
lack  of  development  of  the  cerebral  (inhibiting)  centres 
and  by  the  instability  of  the  cerebellar  mechanisms  which 
responded  to  unilateral  impulses  reaching  it  by  way  of  the 
trigeminus  and  the  nucleo-cerebellar  tract.  Such  abnor- 
mal responses  to  more  or  less  ordinary  stimuli  are  not  un- 
common in  neurotic  individuals,  and  they  may  explain 
many  forms  of  obscure  vertigo  as  that  from  nasal  polypus, 
contact  of  the  skin  with  cold  objects,  e.g.,  the  doctor's 
hand,  etc.  An  interesting  feature  of  this  case  w^as  the  fact 
that  incision  of  the  gum  over  an  erupting  tooth  terminated 
rather  suddenly  an  attack  which,  judging  from  previous 
experience,  seemed  destined  to  last  for  some  weeks. 

Another  interesting  case  of  nystagmus  was  seen  in  the 
first  days  of  an  attack  of  erysipelas  starting  in  an  infant 
of  five  months  over  the  mastoid  area  just  behind  the  left 
auricle.  The  nystagmus,  which  was  of  the  mixed  t}^e, 
had  a  general  direction  toward  the  left  and  with  the  watch, 


834  SEMICIRCULAR   CANALS 

and  was  undoubtedly  due  to  heightened  irritability  of  the 
ampullary  receptors  of  the  superior  and  horizontal  canals 
caused  by  the  local  inflammation.  The  local  application 
of  ice  checked  the  nystagmus  and  helped  to  soothe  the 
severe  gastric  irritability.  The  child  went  on  with  the 
struggle  which  was  a  prolonged  one.  The  disease  spread 
all  over  the  scalp  and  body  with  the  formation  of  numerous 
abscesses,  but  eventually  ended  in  complete  recovery. 
Here  again,  perhaps,  we  must  recognize  lack  of  cerebral 
development  coupled  with  cerebellar  instability  as  the 
fundamental  factor  resulting  in  a  manifest  quantitative 
disproportion  between  effect  and  cause,  the  latter  in  this 
instance  being  of  necessity  a  trivial  difference  of  tempera- 
ture in  the  two  labyrinths  aided  perhaps  by  toxaemia. 
The  nystagmus  disappeared  inside  of  forty-eight  hours. 

Nystagmus  more  frequently  occurs  in  children  than  is 
usually  supposed.  Osier  and  Peterson  ^27  have  reported 
three  cases  occurring  in  young  children  affected  with 
diplegia. 

It  is  possible  to  differentiate  nystagmus  of  central  cere- 
bellar origin  from  that  originating  in  labyrinthine  dis- 
turbances. Nystagmus  due  to  the  latter  has  always  a  fast 
and  a  slow  element,  and  the  movements  are  executed  about 
definite  axes  of  the  eyeball  corresponding  to  rotations  or 
movements  in  fixed  and  definite  planes,  whereas  in  cere- 
bellar nystagmus,  e.g.,  from  a  gross  destructive  lesion  in 
the  vermis,  the  movements  of  the  eyeball  are  apt  to  be 
irregular  in  that  they  occur,  not  about  any  axis  of  the  eye- 
ball, but  are  more  in  the  nature  of  irregular  oscillations 
back  and  forth,  or  circumduction  movements  of  the  eyeball 
as  a  whole.  There  is  an  irregular  inco-ordinated  action  of 
all  or  part  of  the  muscles,  but  no  set  of  opponents  work 
tfjgether  in  such  a  way  that  the  movements  could  be  said 
to  have  a  regular  fixed  direction  as  in  true  nystagnms. 
Moreover,  vohmtarily  turning  the  eyes  in  a  certain  direc- 
tion does  not  inhibit  the  movements  as  in  labyrinthine 
nystagmus,  though  it  may  diminish  them  to  some  extent 
or  develop  abnormal  movements.  However,  some  cases  of 
cerfibf.'llar  nystagnuis  due  in  part  to  destruction  and  in 
part  to  irritation,  may  have  a  definite  direction  and  may 
be  exaggerated  by  turning  the  eyes  in  a  certain  direction, 
thus  resembling  la})yrinthine  nystagmus,  but  in  the  case 
of  cerebellar  nystagmus  there  is  always  some  element  whicb 


PHYSIOLOGY  B85 

would  be  atypical  for  labyrinthine  nystagmus  as  shown 
by  tlie  reactions  to  aural  irrigations,  rotations  and  galvan- 
ism. Thus  in  one  case  due  to  a  syphilitic  deposit  in  the 
vicinity  of  the  vermis,  there  being  no  cerebral  or  cranial 
nerve  symptoms,  the  nystagmus  was  of  the  vertical  type 
and  was  not  affected  by  lying  do\\'Ti.  On  looking  up,  the 
eyes  were  steady,  but  on  looking  toward  the  feet,  the  eye- 
balls began  to  jerk  upward  toward  the  vertex  which  is  op- 
posed to  all  experience  in  the  nystagmus  of  labyrinthine 
origin.  With  this  nystagmus  there  was  an  "empty  feel- 
ing" all  over  the  body  on  the  right  side,  but  with  no 
paralysis  and  no  disturbance  of  the  reflexes  or  loss  of 
cutaneous  sensation.  There  was  slight  inco-ordination  in 
the  right  hand  movements  as  compared  with  the  left.  Ly- 
ing in  bed  with  the  eyes  closed  and  directed  toward  the  feet, 
there  was  experienced  a  sense  of  rotation  in  the  mesial 
plane  "occiput  first."  Sitting  up  with  the  eyes  closed, 
there  was  experienced  a  sense  of  rotation  about  the  long 
axis  from  right  to  left.  The  hearing  was  good  on  both  sides, 
and  there  were  no  noises  in  the  ears.  All  combinations  of 
aural  irrigations  were  tried,  with  the  subject  in  the  supine 
posture.  Bilateral  irrigations  at  61°  F.  caused  the  eyes  to 
jerk  furiously  both  on  looking  up  and  down,  whereas  bi- 
lateral irrigations  at  116°  F.  caused  the  eyes  to  jerk  upward 
upon  looking  toward  the  vertex,  but  absolutely  stopped  all 
motion  upon  looking  toward  the  feet.  These  symptoms  and 
signs  made  probable  the  diagnosis  of  a  lesion  affecting  the 
posterior  portion  of  the  middle  lobe  of  the  cerebellum  and 
extending  somewhat  to  the  left  from  the  middle  line,  the 
paresis  in  the  muscles  being  in  this  instance  in  the  inferior 
recti.  The  peculiar  numb  empty  feeling  on  the  right  side 
of  the  body  extended  from  the  head  to  the  foot.  A  simi- 
lar feeling  was  noted  in  aural  irrigations  but  it  never  ex- 
tended much  below  the  head  and  neck.  This  symptom 
seems  to  be  characteristic  of  cerebellar  disturbance  and 
should  be  carefully  studied  in  every  case  before  being 
classed  as  merely  one  of  the  parsesthesiae.  Another  curious 
symptom  this  patient  presented  was  amenorrhoea  for  a 
period  of  one  year.  Her  menstrual  flow  returned  two  weeks 
after  the  commencement  of  mercurial  inunctions  coupled 
with  iodide  of  potassium  internally.  The  amenorrhoea 
was  probably  only  indirectly  associated  with  the  cerebellar 
lesion.     Formerly  the  cereJjellum  was  supposed  by  physi- 


836  SEMICIRCULAR  CANALS 

ologists  to  be  functionally  related  to  the  sexual  organs. 
Ferrier  ^  in  his  experiments  found  nothing  to  support  such 
a  view.  In  the  present  instance  the  amenorrhoea  was 
merely  the  result  of  general  ill-health  and  anaemia  conse- 
quent upon  the  syphilitic  infection. 

The  importance  of  the  labyrinthine  mechanisms  in 
equilibration  has  long  been  recognized  by  physiologists. 
We  have  seen  the  scope  and  nature  of  some  of  their  rela- 
tions in  this  respect.  We  have  also  seen  that  they  have 
important  relations  with  ocular  movements,  and  with  cir- 
culatory and  respiratory  as  well  as  with  gastric  and  intes- 
tinal function.  Their  delicacy  as  evinced  in  the  foregoing 
experiments,  and  the  possibility  of  latent,  hereditary,  or 
acquired  defect,  coupled  with  their  important  and  exten- 
sive relations,  give  these  mechanisms  a  new  importance 
in  the  etiolog}^  and  treatment  of  neurasthenias,  both  local 
and  general,  as  well  as  of  the  various  neuroses,  and  espe- 
cially those  associated  with  disturbed  gastric  function. 
The  behaviour  of  the  stomach  in  rotations  and  in  aural 
irrigations,  points  to  these  cerebellar  and  labyrinthine 
mechanisms  as  a  possible  factor  in  the  etiology  of  hyper- 
trophic stenosis  of  the  pylorus  in  infants  and  adults. 

The  relations  of  the  cerebellum  to  the  cerebrum,  are 
not  so  clearly  defined,  but  there  is  enough  evidence  to  show 
the  existence  of  impoitant  afferent  and  efferent  cerebellar 
paths  between  these  two  organs.  This  is  a  further  reason 
for  according  the  cerebellum  and  its  mechanisms  an  im- 
portant role  in  the  etiology  of  neuroses  and  neurasthenias, 
in  which  hurry  and  restlessness,  both  physical  and  psychic, 
are  such  features.  Migraine  also  is  undoubtedly  related  to 
some  defect  in  the  cerebellar  mechanisms,  and  the  fact  that 
it  is  said  to  yield  to  hypnotic  suggestion,  can  probably 
be  explained  by  the  afferent  and  efferent  relations  between 
the  cerebellum  and  the  cerebrum.  The  importance  of  the 
afferent  cerebellar  paths,  especially  those  associated  with 
the  eye  and  ear,  should  be  constantly  remembered.  A 
trifling  defect  in  either  of  these  organs,  although  in  time 
it  may  be  compensated,  may  be  sufficient  to  impair  the 
automatic  mechanisms  to  such  an  extent  that  the  individ- 
ual has  to  devote  an  undue  amount  of  concentration,  time, 
and  energy,  to  the  performance  of  ordinary  acts.  The 
result  is  a  handicap  for  the  individual,  and  perhaps  im- 
pairment of  the  general  health. 


PART  III 

SEASICKNESS 


CHAPTER  XXIV 

STUDIES   IN   SEASICKNESS 

On  December  27,  1908,  observations  of  the  circulation 
and  blood-pressure  were  taken  aboard  the  steamship 
Taurus.  The  round  trip  lasted  about  eight  hours.  The 
weather  was  mild,  but  there  was  sufficient  rolling  and 
pitching  to  affect  subject  "B"  who  was  very  susceptible, 
and  yet  not  enough  to  interfere  directly  with  the  correct 
observation  of  the  blood-pressure,  or  indirectly  by  neces- 
sitating balancing  efforts  on  the  part  of  the  subject.  See 
protocols  at  the  end  of  Chapter  XXIX. 

Protocol  1  shows  the  results  of  observations  made  on 
this  trip.  After  the  start,  there  were  signs  of  reaction  on 
the  part  of  the  circulatoiy  mechanisms  resembling  those 
seen  after  mild  rotations  and  aural  irrigations.  The  first 
portion  of  the  protocol  represents  the  condition  of  the  cir- 
culation after  the  exertion  and  excitement  of  trying  to 
catch  the  boat.  After  a  time,  however,  the  blood-pressure 
and  pulse-rate  fell  steadily  as  the  result  of  fatigue  of  the 
vaso-constrictor  mechanisms  (not  well  shown  in  the  proto- 
col because  the  blood-pressure  was  not  taken  sufficiently 
often)  and  of  stimulation  of  the  vagus  centre.  The  slow 
pulse-rate  shown  between  10  a.m.  and  11  a.m.  is  very 
unusual  fcr  this  particular  subject,  and  undoubtedly  rep- 
resents mild  vagus  stimulation.  The  recovery  of  the  vaso- 
constrictor mechanism  from  12.80  p.m.  on,  when  the  boat 
was  at  rest  and  the  machinery  stopj)ed  is  worthy  of  note. 
The  chief  symptoms  experienced  by  the  subject  were  a 
slight  headache,  and  the  familiar  "  queer  feeling  all  over" 
which  was  present  only  at  times.  In  addition  to  these 
there  were  slight  disturbances  of  the  nervous  system,  as 
manifested  by  disinclination  for  work,  irritability  of  tem- 
per, and  a  consciousness  of  the  respiratory  movements. 
Long,  deep  inspirations  were  a  matter  of  frequent  occur- 
rence. 

339 


840  SEASICKNESS 

On  April  4,  1909,  another  trip  was  made  upon  the 
steamship  A  ngler.  On  this  occasion  frequent  observations 
on  the  pulse-rate  and  iDlood-pressure  were  made.  The  trip 
lasted  about  seven  hours  and  a  half.  The  weather  was 
mild,  but  there  was  enough  motion  to  produce  the  subjec- 
tive phenomena  of  seasickness  in  its  early  and  milder 
phases.  The  nervous  manifestations  were  headache,  with 
fulness  and  lightness  in  the  head,  parsesthesise  of  the  scalp, 
especially  a  sense  of  tension  in  the  occipital  region,  psy- 
chic and  motor  depression,  irritability  of  temper,  disin- 
clination for  work,  perversion  of  sensory  function,  whereby 
the  respiratory  and  gastro- intestinal  movements  were 
registered  in  consciousness,  perversion  of  the  sense  of 
smell,  whereby  the  odour  of  tobacco-smoke,  agreeable  under 
ordinary  circumstances,  became  obnoxious,  photophobia, 
and  annoyance  from  the  use  of  the  eyes,  especially  in  look- 
ing at  the  moving  water  (fatigue  of  the  oculo-motor  ap- 
paratus ) . 

The  changes  in  the  circulation,  as  shown  in  protocol  2, 
were  not  striking,  nevertheless  they  show  the  characteristic 
reaction  of  the  circulatory  system  to  repeated  irritation  of 
the  medullary  centres,  and  though  milder  in  degree,  re- 
semble those  changes  so  constantly  met  with  in  rotations 
and  aural  irrigations.  All  through  the  trip  the  vaso-motor 
mechanism  was  in  a  constant  state  of  activity  in  response 
to  mild  stimulation  of  the  labyrinthine  receptors.  The 
movements  of  the  boat  were  not  of  sufficient  abruptness 
and  range  to  cause  overirritation  with  subsequent  exhaus- 
tion. Hence  the  protocol  shows  rather  an  enhancement  of 
the  circulation,  with  a  slowing  of  the  pulse,  the  latter  in 
great  part  the  result  of  mild  stimulation  of  the  cardiac 
vagus  centre.  These  observations  show  that  even  in  the 
presence  of  unimpaired  circulation,  all  the  subjective  phe- 
nomena of  seasickness  may  be  present.  It  follows,  there- 
fore, that  the  prime  cause  of  seasickness  is  not  impaired 
circulation,  although  profound  changes  in  the  circulation 
may,  and  usually  do,  occur  in  any  given  case. 

Digestive  disturbances  appeared  early.  The  "lump- 
sensation"  in  the  stomach — i.e.,  a  feeling  as  if  a  foreign 
body  were  in  that  organ,  is  one  of  the  early  symptoms  of 
seasickness,  just  as  it  is  in  the  sickness  of  rotations  and 
aural  irrigations.     This  symptom  results   in  part   from 


SEASICKNESS  841 

sensory  perversion,  and  in  part  from  overactivity  of  the 
muscles  of  the  stomach,  both  of  which  are  in  turn  to  be 
attributed  to  irritation  of  the  medullary  and  cerebral  cen- 
tres. On  different  occasions  the  stomach  was  evacuated 
and  irrigated,  to  determine  the  cause  of  this  "lump-sen- 
sation. ' '  In  many  instances  a  mass  of  mucus  was  re- 
covered, but  this,  though  of  importance  as  a  secondary 
factor,  could  not  be  considered  the  prime  cause,  as  it  fre- 
quently happened  that  no  such  disturbing  element  was  to 
be  found  within  the  stomach,  and  where  such  was  found, 
the  symptom  often  persisted  after  its  removal.  In  sup- 
port of  this  view,  may  be  cited  the  concomitant  slowing 
of  the  pulse  in  seasickness  and  in  rotation-  and  irrigation- 
sickness,  as  well  as  the  vaso-motor  changes,  nausea,  in- 
creased salivation,  yawning,  deep,  sighing  respirations, 
and  other  symptoms,  all  of  which  point  to  disturbed  func- 
tion in  the  medullary  centres. 

On  May  30,  1909,  further  observations  were  made  on 
the  steamship  Angler.  The  trip  lasted  about  eight  and  a 
half  hours,  during  which  observations  on  the  pulse-rate 
and  blood-pressure  were  made  almost  constantly.  The 
results  are  recorded  in  protocol  8.  The  weather  was  mild. 
There  was  rather  more  motion  to  the  boat  than  on  the 
previous  occasions.  An  early  start  was  made  for  the  boat, 
so  as  to  avoid  the  effects  of  rush  and  hurry  upon  the  cir- 
culation. No  food  had  been  taken  since  the  previous 
night,  so  that  a  test  meal  could  be  given,  and  observations 
made  on  the  functions  of  digestion,  etc.  The  figures  re- 
corded down  to  10.24  a.m.  show  but  little  effect  upon  the 
circulation,  and  yet  the  subject  experienced  most  of  the 
symptoms  of  seasickness  of  mild  grade,  e.g. ,  "lump-sensa- 
tion" in  the  stomach,  increased  secretion  of  saliva,  head- 
ache, fulness  in  the  head,  dizziness,  pain  in  the  eyes,  dis- 
inclination for  work  or  effort  of  any  kind.  The  figures 
from  10. 24  to  12.38  p.m.  show  practically  the  same  thing, 
although  there  was  considerable  rolling  of  the  boat  during 
this  period.  The  subjective  sjmiptoms  were  increased. 
Food  was  taken  with  the  result  that  it  subsequently  caused 
pain  in  the  stomach.  Occipital  headache  and  pain  in  the 
back  of  the  neck  upon  the  right  side  were  features  of  this 
period. 

The  blood-pressure  showed  a  slight  downward  tendency. 


a42  SEASICKNESS 

From  12.38  until  2,  vaso-motor  fatigue  was  in  evidence, 
with  a  steady  decline  in  blood-pressure.  The  pulse-rate 
was  increased  to  meet  the  failure  of  the  vaso-motor  system. 
The  subjective  symptoms  of  this  period  included  nausea, 
headache,  par8esthesio3  of  the  scalp,  irritability  of  temper, 
muscular  weakness  and  tremors.  Eructations  were  fre- 
quent. Between  2  and  3.85  there  was  general  fatigue, 
and  especially  fatigue  of  the  vaso-motor  mechanism  with 
the  pulse-rate  moderately  increased.  The  subjective  symp- 
toms persisted,  causing  general  wretchedness.  About 
8.50,  there  was  a  tendency  to  recovery  on  the  part  of  the 
vaso-motor  mechanism,  with  a  drop  in  the  pulse-rate. 
The  general  condition  of  the  circulation  was  fair,  and  yet 
the  subject's  condition  was  far  from  good.  The  symptoms 
were :  pain  in  the  muscles  of  the  back  of  the  neck,  upon 
the  right  side,  extending  up  into  the  occiput,  general 
weakness,  and  sweating,  "lump-sensation,"  eructations, 
dull  ache  in  the  eyeballs.  All  through  the  trip  the  arteries 
were  alternately  contracting  and  dilating.  The  general 
effect  upon  the  circulation  was  to  induce  fatigue,  with  a 
consequent  fall  in  the  blood-pressure.  An  Ewald  break- 
fast was  given  subject  "B,"  and  allowed  to  remain  in  the 
stomach  1  hour  and  54  minutes.  The  K  I  absorption  test 
showed  iodin  in  the  saliva  in  54  minutes.  The  motility 
test  showed  salol  in  the  intestine  in  2  hours  and  2  min- 
utes. The  amount  of  chyme  recovered  was  about  ^vi. 
This  had  to  be  computed,  as  the  subject  vomited  on  in- 
troduction of  the  stomach-tube.  Analysis  of  the  filtered 
gastric  juice  showed  total  acidity,  .13%  by  weight;  free 
HCl,  .05%;  combined  HCl,  .06%.  A  trace  of  blood  was 
found  in  the  chyme,  as  the  result  of  straining  and  con- 
gestion during  the  vomiting.  There  was  no  other  abnor- 
mality. Analysis  after  a  test  meal  given  to  subject  "S" 
on  the  same  trip  and  retained  1  hour  and  12  minutes 
showed:  total  acidity,  .86%;  free  HCl,  .26;  combined 
HCl,  .09,  with  the  K  1  test  positive  in  12  minutes,  and 
the  salol  test  positive  in  1  hour  and  7  minutes.  This 
subject,  however,  has  little  susceptibility — at  least  he  is 
not  affected  in  weather  such  as  that  which  prevailed  on 
this  occasion.  Moreover,  he  is  by  times  a  boatman  and 
"follows  the  water"  as  a  business. 


SEASICKNESS  343 

Analysis  of  specimen  taken  May  30,  1909,  from  subject  "B" 
aboard  the  Angler.  Ewald  meal  taken  on  fasting  stomach 
at  8.30  a.m.  and  withdrawn  at  10.24.  Amount  of  chyme, 
§vi.  Resorcin  test  for  free  HCl  positive,  but  feeble  reac- 
tion: 

Tot.  acidity,  38,  or  .13%  by  wt.  Other  enzymes,  normal 

Free  HCl,  14,  or  .05%  by  wt.  Starch,  absent. 

Comb'd  HCl,  18, or  .06%  by  wt.  Amylodextrin,  absent. 

Total  HCl,  32,  or  .11%  by  wt.  Erythrodextrin,  trace. 

Acid  salts,  6,  or  .02%  by  wt.  Maltose,  present. 

Lactic  acid,  absent.  Bile,    absent. 

Peptonizing   enzymes,    dimin-  Blood,    present  in  small   amt. 

ished.  Mucus,  very  small  amount. 

Analysis  of  specimen  taken  May  30,  1909,  from  subject  "S" 
aboard  the  Angler,  Ewald  meal  ingested  at  8.30  a.m.  on 
fasting  stomach;  withdrawn  at  9.42.  Amount  of  chyme 
§iii.     Resorcin  test  for  free  HCl  positive. 

Tot.  acidity,    100,  or  .36%  by  Enzymes,  normal. 

wt.  Starch,  absent. 

Free  HCl,  72,  or  .26%  by  wt.  Amylodextrin,  present. 

Comb'd  HCl,    26,  or  .09%   by  Erythrodextrin,  present. 

wt.  Maltose,  present. 

Total  HCl,  98,  or  .35%  by  wt.  Bile,  absent. 

Acid  salts,  2,  or  .007%  by  wt.  Blood,  absent. 

Lactic  acid  (direct  and  ether),  Mucus,  very  little. 

absent. 

On  May  31,  1909,  a  trip  lasting  one  hour  was  made  in 
the  motor  launch  Maggie.  Observations  on  the  pulse  and 
blood-pressure  were  made  almost  continuously  through- 
out the  trip. 

Protocol  4  shows  the  results.  The  subject  "B"  was 
somewhat  fatigued  before  the  start.  There  was  little  in 
the  way  of  a  swell  upon  the  water,  and  yet  the  boat  pitched 
and  rolled  somewhat.  The  circulation  all  through  the  trip 
showed  slight  fluctuations,  but  the  arteries  nevertheless 
were  constantly  contracting  and  dilating.  At  times  the 
blood-pressure  was  rather  low,  but  this  was  in  part  due  to 
previous  fatigue.  Even  in  the  fresh  breeze,  there  were 
some  subjective  symptoms,  such  as  "lump-sensation"  in 
the  stomach,  and  a  "queer  sick  feeling"  in  the  head,  as 
well  as  deep,  long  drawn  breaths  and  eructations.  These 
symptoms  were  present  in  spite  of  the  fact  that  the  sub- 
ject was  not  feeling  badly.  In  the  second  half  of  the  trip, 
the  pulse-rate  showed  a  tendency  to  slowing,  in  spite  of 


344  SEASICKNESS 

the  low  blood-pressure.     Note  at  the  commencement  of  the 
protocol,  the  effect  of  recumbency  upon  the  circulation, 
when  vaso-motor  fatigue  has  supervened. 
The  conclusions  are: 

1.  That  in  the  beginning  of  seasickness,  the  blood- 
pressure  may  show  slight  changes,  the  effects  in  general 
being  a  slight  rise. 

2.  That  the  arteries  are  constantly  contracting  and 
dilating,  the  tendency  in  general  being  toward  a  state  of 
contraction. 

3.  That  the  pulse-rate  varies  somewhat  with  the  con- 
traction and  dilatation  of  the  arteries,  the  chief  feature 
being  a  tendency  to  slowing,  with  some  rhythmic  irregu- 
larity. 

4.  That  cerebral,  gastric  and  other  "dolors"  occur 
simultaneously  with  unimpaired  or  even  with  enhanced 
circulation. 

5.  That  digestive  disturbances  even  in  the  milder 
phases  of  seasickness  set  in  early,  and  form  an  important 
and  constant  feature  in  the  train  of  phenomena. 

6.  That  the  phenomena  of  seasickness  seem  identical 
with  those  of  rotation-and  aural-irrigation-sickness. 

7.  That  disturbed  circulation  is  not  the  prime  cause 
of  seasickness. 

8.  That  gastric  and  circulatory  disturbances,  however 
much  they  may  contribute  as  secondary  causes  to  the  phe- 
nomena of  seasickness,  are  not  the  prime  cause,  but  are 
themselves,  together  with  the  psychic  and  motor  depression 
and  the  other  phenomena,  the  result  of  irritation  of  the 
medullary,  cerebellar  and  cerebral  centres. 


CHAPTER  XXV 

FURTHER   STUDIES   IN   SEASICKNESS   DURING  A 
TRANSATLANTIC  TRIP 

On  June  26,  1909,  a  trip  was  commenced  from  New 
York  to  Glasgow,  on  board  the  steamship  Caledonia  of 
the  Anchor  Line.  Observations  of  the  circulation  were 
made  at  frequent  intervals  during  each  day.  The  passage 
was  not  rough,  there  being  just  enough  motion  to  afford 
an  ideal  opportunity  of  testing  the  prolonged  effects  of 
mild  irritation  upon  the  nervous,  circulatory  and  digestive 
mechanisms.  Protocol  5  shows  the  effects  of  the  first  day's 
sailing  upon  the  blood-pressure  and  pulse.  Almost  im- 
mediately after  the  start,  typical  symptoms  of  mild  sea- 
sickness set  in.  The  boat  started  at  2.22  p.m.,  and  by 
3  o'clock  the  subject  experienced  the  familiar  "lump- 
sensation"  in  the  stomach,  increased  salivary  flow,  per- 
verted sense  of  smell  (the  odour  of  tobacco-smoke  being 
offensive),  occipital  headache,  especially  in  the  region  of 
the  right  mastoid  and  parsesthesiae  of  the  scalp  (e.g., 
' ' cap' '  sensation) .  With  these  there  were  eructations  and 
a  considerable  decline  in  blood-pressure,  with  increased 
pulse-rate.  These  phenomena  are  undoubtedly  character- 
istic of  seasickness,  but  there  was  practically  no  motion 
to  the  boat  which  could  produce  such  symptoms,  for  w^e 
were  scarcely  out  of  the  harbour  and  the  sea  was  as  calm 
as  a  lake.  An  explanation  of  the  symptoms  therefore  has 
to  be  sought  elsewhere.  The  subject  was  an  old  victim 
of  the  sea,  having  crossed  the  ocean  about  fifty  times,  and 
never  once  without  suffering  from  seasickness  in  one  form 
or  another.  On  one  occasion  he  had  an  experience  which 
throws  considerable  light  on  the  phenomena  just  detailed. 
He  had  been  in  the  habit  of  crossing  in  the  smaller  boats 
of  the  Anchor  Line,  and  had  come  to  the  conclusion  that 
the  equino:^e§  were  not  the  most  favourable  times  for  go- 

345 


846  SEASICKNESS 

ing  to  sea.  On  this  occasion,  however,  circumstances 
compelled  him  to  cross  in  the  beginning  of  April,  and  a 
cabin  was  secured  in  the  steamship  Astoria^  which  was  a 
comparatively  small  boat.  The  date  of  sailing  was  fixed 
for  Sunday,  and  on  Saturday  afternoon  a  visit  was  made 
to  inspect  the  boat.  It  was  a  dismal,  dreary  day.  Every- 
thing was  hurry  and  bustle  with  the  crew.  Things  were 
in  a  state  of  chaos  on  board,  as  might  be  expected.  The 
stewards  were  scurrying  about  without  uniforms,  the 
decks  were  in  disorder,  and  everything  was  so  differ- 
ent from  the  conditions  that  obtain  on  the  open  sea,  where 
orderliness,  discipline,  and  white,  spotless  decks  are  the 
rule.  The  appearance  of  things  was  distinctly  discourag- 
ing. This,  coupled  with  the  thought,  that  at  that  par- 
ticular time  of  the  year,  a  rough  passage  was  to  be  ex- 
pected, greatly  depressed  the  prospective  traveller.  In 
such  a  frame  of  mind  he  went  below,  to  inspect  his  cabin. 
The  odour  and  gloom  between  decks  overpowered  him  to 
such  an  extent  that  he  became  dizzy  and  nauseated,  and 
experienced  much  of  the  distress  that  is  associated  with 
genuine  seasickness.  In  fact  at  each  step  on  the  deck, 
the  latter  seemed  to  sink  beneath  his  feet,  as  with  a  gentle 
rolling  motion,  and  with  all  the  tantalizing,  sickening 
effects  that  such  a  motion  can  have  upon  the  seasick  brain. 
The  subject  left  the  boat.  His  seasickness  persisted,  how- 
ever, for  quite  some  time  as  he  travelled  homeward  by 
street-car.  It  should  be  mentioned  that  although  the  sub- 
ject is  very  susceptible  to  seasickness,  he  is  not  at  all 
affected  by  the  motions  of  trains  or  street-cars.  The  out- 
look for  the  journey  was  dismal.  From  past  experience 
he  knew  that  but  little  food  would  pass  his  lips  during 
the  coming  eight  days.  However,  he  grimly  determined 
to  make  the  most  of  it,  and  so  set  about  eating  as  much 
as  he  could  conveniently  digest,  with  the  hope  of  storing 
his  organs  with  an  available  supply  of  energy  for  the 
days  of  privation  to  come.  Heavy  meals  were  the  order 
of  the  day  even  to  the  minute  the  boat  sailed.  Finally 
the  journey  was  commenced,  and  now  all  the  feasting  was 
over,  and  nothing  remained  but  to  wait.  The  passage 
was  a  very  rough  one.  Most  of  the  passengers  were  dread- 
fully ill  for  days,  but  not  this  one,  who,  although  slightly 
affected,  never  missed  making  an  appearance  ^t  me^l-time, 


SEASICKNESS  847 

In  fact  it  was  the  least  disagreeable  passage  he  had  ever 
had.  It  should  be  stated,  however,  that  the  weather  was 
very  cold,  and  the  subject's  cabin  well  ventilated  during 
the  whole  journey.  This  experience  opens  up  the  ques- 
tion of  the  influence  of  the  imagination  in  the  etiology  of 
seasickness.  Unquestionably  the  imagination  plays  an 
important  part.  Coupled  with  subconscious  memories  of 
past  experiences,  it  may  be  a  powerful  factor,  and  is  al- 
ways an  important  secondary  source  of  discomfort.  It 
must  not  be  considered,  however,  as  the  primary  cause  of 
seasickness.  The  phenomena  of  the  early  part  of  this  first 
day's  sailing  on  the  Caledonia  may,  therefore,  be  attrib- 
uted to  fatigue  and  excitement  backed  by  strong  subcon- 
scious memories  and  by  present  impressions  and  associa- 
tions. And  here  once  and  for  all,  impressionability  is  to 
be  distinguished  from  fear,  for  in  spite  of  his  experiences 
of  the  sea,  the  subject  was  never  afraid  of  seasickness  and 
never  "gave  in"  to  it,  as  the  expression  goes. 

After  dinner,  at  7  p.m.,  the  absorption  and  motility 
tests  were  tried.  A  positive  reaction  for  iodin  in  the 
saliva  was  found  in  2  hours  and  17  minutes,  whilst  salol 
was  found  to  be  present  in  the  intestine  in  2  hours  and 
22  minutes.  Absorption  evidently  occurred  only  after 
food  has  passed  into  the  intestine,  for  all  through  the 
tests,  the  salivary  flow  was  free. 

Toward  night  there  were  still  present:  headache,  and 
"lump-sensation"  in  the  stomach  and  throat.  The  cir- 
culation was  very  much  depressed,  on  account  of  vaso- 
motor fatigue  induced  in  part  by  heat  and  exhaustion, 
and  in  part  by  the  motions  of  the  ship.  The  behaviour 
of  the  circulation  upon  lying  down  as  shown  in  protocol 
5,  where  the  pulse-rate  suddenly  makes  an  extensive 
downward  excursion,  whilst  the  blood-pressure  makes  a 
correspondingly  sudden  and  extensive  upward  excursion, 
indicates  exhaustion  of  the  vaso-motor  apparatus,  the 
dynamics  of  the  circulation,  especially  the  return  flow  to 
the  heart,  being  favoured  mechanically  in  recumbency. 
Such  variations  of  pulse-rate  and  blood-pressure  when 
represented  in  charts,  show  divergent  and  overlapping 
curve  loops  which  are  common  features  of  seasickness 
and  of  circulatory  fatigue  in  general  and  which  afford  an 
important  clue  as  to  the  method  of  treatment. 


348  SEASICKNESS 

The  urine  during  this  day  was  rather  heavy,  the  speci- 
fic gravity  at  different  times  being  1.086,  and  1.038,  with 
a  marked  reaction  for  glycuronic  acid.  The  amount  passed 
was  low,  considering  the  liberal  amount  of  fluid  taken 
during  the  day.  The  warm  weather  and  free  sweating 
were  factors  in  the  diminished  amount  of  urine,  though 
the  disturbed  circulation  undoubtedly  played  a  part.  On 
the  day  previous  to  sailing,  the  urine  showed  a  specific 
gravity  of  1.080  with  no  glycuronic  acid  or  merely  a  trace. 

During  the  first  night  at  sea  the  subject  slept  fairly 
well  but  was  disturbed  by  dreams. 

June  27th.  — The  subjective  symptoms  were  very  mild  on 
this  day,  and  were  perhaps  to  be  attributed  to  the  hot 
weather,  and  to  general  fatigue  as  much  as  to  the  motions 
of  the  boat.  The  digestive  symptoms  were  those  of  the 
"lump-sensation"  in  the  stomach  and  throat,  which  was 
present  at  various  times  during  the  day,  and  eructations. 
The  absorption  test  showed  iodin  in  the  saliva  in  21 
minutes  after  the  midday  meal.  The  motility  test  was 
not  tried,  because  there  were  still  traces  of  salicyluric  acid 
in  the  urine  since  the  test  of  the  previous  day.  Occipital 
headache  was  present,  with  a  tired  feeling  about  the  eyes. 

Protocol  6  shows  the  effects  upon  the  circulation. 
The  blood-pressure  was  rather  low,  even  after  a  fair  night's 
rest  and  the  morning  cold  tub.  The  pulse-rate  and  blood- 
pressure  indicate  vaso-motor  exhaustion,  whilst  the  steady 
drop  in  the  pulse-rate  indicates,  in  the  presence  of  low 
blood-pressure,  irritation  of  the  vagus  centre. 

The  urine  on  this  day  was  somewhat  increased,  the 
specific  gravity  at  different  times  being  1.034,  1.080,  and 
1.028,  with  a  less  marked  reaction  for  glycuronic' acid. 

June  28th. — On  this  day  the  notes  make  no  mention  of 
subjective  symptoms.  The  urine  had  increased  in  amount, 
and  was  about  the  normal  for  this  particular  subject. 
The  specific  gravity  at  various  times  was  1.028,  1.024, 
and  1.020.  A  mere  trace  of  glycuronic  acid  was  present. 
Regular  meals  were  eaten  and  caused  no  trouble.  The 
bowels  were  constipated  from  the  beginning  of  the  journey, 
so  that  cascara  sagrada  was  taken  on  retiring. 

Protocol  7  shows  a  decided  improvement  in  vaso-motor 
tonus  due,  in  part  perhaps,  to  the  effects  of  the  cold 
plunge,  and  the  general  tendency  of  the  vaso-motor  system 
to  recover  under  the  influence  of  cooler  weather.     The  fig- 


SEASICKNESS  849 

ures  indicating  the  pulse-rates  and  blood-pressures,  when 
represented  in  chart  form,  showed  less  divergence  of  the 
curve  loops  upon  lying  down.  The  blood-pressure  was 
well  maintained  under  the  influence  of  improved  vaso- 
motor tonus.  The  pulse-rate  was  uniformly  low.  The  ef- 
fect of  sound,  refreshing  sleep  is  well  shown,  the  pulse  and 
pressure  curves  running  along  uniform  and  parallel  lines. 

June  29th. — This  was  a  cold,  foggy  day.  The  ship 
commenced  rolling  during  the  night,  and  continued  to  roll 
all  through  the  day.  The  result  was  a  return  of  the  sub- 
jective symptoms,  viz.,  "lump-sensation"  in  stomach, 
fulness  and  lightness  in  the  head,  occipital  headache,  flush- 
ing of  the  face,  aching  and  heaviness  about  the  eyes,  ful- 
ness in  the  ears,  parsesthesise  of  the  scalp,  psychic  and 
motor  depression,  and  irritability  of  temper  with  a  ten- 
dency to  worry  about  trifles. 

Protocol  8  shows  the  effects  upon  the  circulation. 
There  was  a  return  of  the  vaso-motor  exhaustion,  which 
the  cold  plunge  did  not  appreciably  benefit.  There  was  a 
return  also  of  the  diverging  and  converging  curve  loops, 
representing  the  pulse-rates  and  blood-pressures,  notwith- 
standing the  coldness  of  the  weather,  and  a  thorough 
evacuation  of  the  bowels.  The  porthole  was  closed  all 
day,  but  in  spite  of  this  fact  the  temperature  of  the  air 
in  the  cabin  was  rather  low. 

After  the  midday  meal,  the  absorption  and  motility 
tests  were  made.  The  salol  and  K  I  reactions  appeared 
simultaneously  in  2  hours  and  16  minutes. 

The  urine  was  normal  in  amount  and  specific  gravity, 
the  latter  being  at  various  times  1.020,  1.022,  etc. 

June  30th. — On  this  day  the  ship  rolled  and  pitched 
considerably,  especially  from  the  early  afternoon  on  into 
the  night.  The  subject  felt  very  well  in  the  forenoon,  but 
as  time  went  on,  the  symptoms  of  mild  seasickness  re- 
turned, with  slight  headache,  and  a  feeling  of  dulness  and 
heaviness.  The  "lump-sensation"  was  present  in  the 
stomach  and  throat,  and  with  it  a  feeling  of  fulness  and 
lightness  in  the  head.  At  times  there  was  a  feeling  as  if 
"the  top  was  being  raised  off  the  head. "  The  saliva  was 
increased,  and  the  eyes  ached.  There  was  fulness  in  the 
ears,  and  a  burning  sensation  in  the  stomach.  The  ab- 
sorption test  was  tried  after  the  midday  meal,  and  iodin 
found  in  the  saliva  in  B  hours  and  24  minutes. 


350  SEASICKNESS 

At  6.80  p.m.,  dinner  was  over.  There  was  consider- 
able rolling  and  pitching  during  the  whole  evening.  The 
motions,  however,  were  slow  and  regular.  The  subject 
experienced  no  bad  feeling,  but  gradually  all  the  phenom- 
ena of  disturbed  digestion  appeared,  with  increased  secre- 
tion of  saliva,  "lump-sensation"  in  the  throat  and  stom- 
ach, ringing  in  the  ears,  fulness  in  the  head,  etc.  At 
11  p.m.,  the  contents  of  the  stomach  were  removed, 
and  that  organ  irrigated.  A  burning  sensation,  present 
before  irrigation,  persisted  in  spite  of  the  latter.  Analy- 
sis showed  the  presence  of  a  moderate  excess  of  mucus 
and  of  lactic  acid  with  total  acidity,  .18%  by  weight,  free 
HCl  .18,  and  combined  HCl  .05. 

Analysis  of  specimen  taken  June  30th  from  subject  "B."  In- 
gested at  6  p.m.  a  meal  consisting-  of  macaroni,  brown 
bread  with  butter,  1  cup  of  tea,  and  some  marmalade.  With- 
drawn at  11  p.m.  Amount  of  chyme  §iv,  but  a  large 
amount  was  lost  by  vomiting.  Resorcin  test  showed  the 
presence  of  free  HCl. 

Tot.  acidity,    52,   or  .18%   by  Starch,  absent. 

wt.  Amylodextrin,  absent. 

Free  HCl,  38,  or  .13%  by  wt.  Erythrodextrin,  present. 

Comb'd  HCl,    14,  or  .05%  by  Achroodextrin,  present. 

wt.  Maltose,  present. 

Tot.  HCl,   52,  or  .18%  by  wt.  Peptones,  present. 

Acid  salts,  .  Bile,  absent. 

Blood,  absent. 

Lactic  acid  (direct),  present.  Mucus,  moderate  excess. 

Absorption  and  motility  tests  not  made. 

The  condition  of  the  circulation  during  the  day  is 
shown  in  protocol  9.  In  the  early  part  of  the  day  the 
vaso-motor  tone  was  fair,  the  response  to  the  cold  plunge 
being  fairly  good.  As  the  day  wore  on,  however,  and  es- 
pecially with  the  onset  of  the  subjective  symptoms  and  of 
disturbed  digestion,  the  vaso-motor  mechanism  showed 
evidence  of  fatigue,  with  lowered  blood-pressure  and  in- 
creased pulse-rate. 

The  urine  on  this  day  was  normal  in  amount.  The 
specific  gravity  at  various  times  was  1.018,  1.016,  and 
1.018.  The  subject  was  taking  fluids  freely.  The  weather 
was  no  longer  very  warm,  consequently  there  was  less 
sweating. 

July  1st. — The  boat  rolled  and  pitched  considerably 


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SEASICIvXESS  851 

throughout  the  night.  It  was  interesting  to  find  that  even 
whilst  the  subject  was  lying  in  bed,  the  motions  of  the 
boat  produced  their  usual  characteristic  effects  in  disturb- 
ing the  organic  functions,  but,  as  in  rotations  and  aural 
irrigations,  these  disturbances  did  not  cause  nausea,  vom- 
iting, and  the  usual  extreme  wretchedness,  so  long  as  the 
subject  lay  quietly  in  bed.  All  the  subjective  phenomena 
of  seasickness  were  present  on  this  day,  the  subject  being 
too  ill  to  take  breakfast.  Especially  noticeable  were  the 
parsesthesiae  of  the  scalp  over  the  right  side  of  the  occiput, 
and  within  the  right  ear  in  which  there  was  a  numb  feel- 
ing as  if  there  was  an  exudation  within  the  tympanum. 

Protocol  10  shows  the  extreme  circulatory  depression 
due  to  vaso-motor  exhaustion,  the  result  of  rolling  and 
pitching  during  the  night.  The  vaso-motor  system  failed 
to  respond  properly  to  muscular  exertion,  e.g.,  chinning 
the  bar.  The  respirations  were  increased  to  24  per  min- 
ute, doubtless  as  a  compensation  for  the  demoralized  cir- 
culation and  as  a  direct  aid  to  the  labouring  heart. 

At  10.18  a.m.,  an  Ewald  test  meal  was  given  on  the 
fasting  stomach.  The  absorption  test  showed  iodin  in 
the  saliva  in  28  minutes.  The  stomach  contents  were  re- 
moved at  11.35  a.m.  The  amount  of  chyme  recovered 
was  |ii.  It  contained  a  considerable  amount  of  thick, 
ropy  mucus,  and  toward  the  end  some  pure  blood.  The 
stomach  was  irrigated  when  more  mucus  was  removed  and 
with  it  some  more  fresh  blood.  The  analysis  of  the  gastric 
contents  showed:  total  acidity,  .087%  by  weight;  free 
HCl  absent;  combined  HCl.  .065. 

Analysis  of  specimen  taken  from  "B,"  July  1st.  Ewald  break- 
fast ingested  at  10.18  a.m.  Withdrawn  at  11.35  a.m. 
Amount  of  chyme  fii.  Evidence  of  gross  blood.  Resorcin 
test  showed  absence  of  free  HCl. 

Tot.  acidity,   24,  or  .087%  by  Starch,  absent. 

wt.  Amylodextrin,  trace. 

Free  HCl,  absent.  Erythrodextrin,  present. 

Comb'd  HCl,  18,  or  .065%  by  Achroodextrin,  present. 

wt.  Maltose,  present. 

Tot.  HCl,  18,  or  .065%  by  wt.  Peptones,  present. 

Acid  salts,  .  Bile,  absent. 

Mucus,  considerable  amount. 

Lactic  acid  (direct),  trace.  Blood,  present. 

The  K  I  absorption  test  showed  iodin  in  the  saliva  in  28 


35^  SEASICKNESS 

minutes.  The  salol  motility  test  was  not  made.  The  urine 
was  somewhat  diminished  on  this  day.  The  specific  gravity 
was,  at  various  times,  1.018,  1.016,  and  1.010. 

The  day's  experience  shows  how  it  is  possible  for  an 
individual  at  sea  to  retire  at  night  feeling  in  good  general 
condition  and  to  wake  up  in  the  morning  with  the  circu- 
latory and  digestive  mechanisms  thoroughly  demoralized. 

July  2d. — This  was  a  gloomy  day,  but  the  weather  was 
not  very  rough.  There  was  much  rolling  and  pitching, 
however,  and  all  the  subjective  phenomena  of  seasickness 
were  experienced. 

Protocol  11  shows  the  effects  upon  the  circulation. 
Some  observations  upon  the  blood-pressure  and  pulse-rate 
of  subject  "S"  are  shown  for  comparison  in  protocol  11a. 
The  circulation  was  similarly  affected  in  both  individuals. 
In  both  there  was  evidence  of  vaso-motor  exhaustion. 

Again  it  is  to  be  noted  that  the  cold  tub  had  no  last- 
ing beneficial  effects  upon  the  vaso-motor  mechanism,  so 
that  it  is  a  question  whether  cold  bathing  is  not  harmful 
in  these  cases  in  which  the  vaso-motor  system  is  exhausted 
from  irritation  of  the  medullary  centres.  Indeed  subject 
"B"  had  known  from  long  experience  that  the  morning 
cold  tub  always  seemed  to  aggravate  rather  than  to  help 
the  subjective  phenomena  of  seasickness.  After  the  even- 
ing meal  at  6.21  p.m.,  the  absorption  test  was  tried  and 
iodin  was  not  found  in  the  saliva  in  8^-  hours,  except  for 
a  fleeting  faint  reaction.  However,  the  saliva  reacted 
strongly  for  iodin  on  the  next  morning. 

The  urine  on  this  day  was  normal  in  amount.  The 
specific  gravity  at  various  times  was  1.010,  1.018,  and 
1.020.  At  4. 16  p.m.  the  urine,  with  a  specific  gravity  of 
1.020,  showed  the  presence  of  sugar.  Only  the  test  with 
Fehling's  solution  was  tried,  but  using  every  precaution 
the  conclusion  was  that  the  reducing  agent  was  sugar. 
The  previous  meal  was  taken  at  2.45  p.m.,  and  consisted 
of  pea  soup,  fvi,  boiled  codfish,  ^ii,  potatoes,  a  large 
amount,  one  cup  of  coffee  with  milk  and  sugar,  2  currant 
cakes  (sweet).  At  5.50  p.m.,  the  sugar  had  disappeared 
from  the  urine.  This  meal  contained  an  unusual  excess 
of  sugar.  The  glycosuria  was  therefore  in  part  at  least  of 
the  alimentary  type. 


SEASICKNESS  ~  853 

July  3d. — The  weather  on  this  day  was  rather  raild. 
The  ship,  however,  rolled  and  pitched  considerably.  All 
the  subjective  phenomena  of  seasickness  were  again  ex- 
perienced. Before  breakfast  the  stomach  was  irrigated, 
and  found  to  contain  mucus  and  some  blood.  Protocol 
12  shows  the  effects  upon  the  circulation.  There  was 
marked  vaso-motor  exhaustion.  Protocol  12a  shows  simi- 
lar effects  upon  the  circulation  in  subject  "S."  At  1.39 
p.m.  a  meal  was  taken,  consisting  of  consomme  soup,  ^iv; 
roast  mutton,  about  §11;  potatoes,  a  fair  amount;  water, 
|iii;  sago  pudding,  3ii;  1  cup  of  coffee  and  2  pieces  of  cake 
with  sugar  tops.  The  ship  was  rolling  considerably  and 
the  "lump-sensation"  was  much  in  evidence.  The  sub- 
ject slept  for  about  20  minutes  during  the  afternoon. 
The  effect  of  sleep  is  shown  in  the  protocol,  2.31  p.m.  to 
2.51.  At  5. 35  p.  m. ,  the  stomach  contents  were  withdrawn. 
The  amount  of  chyme  recovered  was  §11.  It  was  sour  smell- 
ing, and  mixed  with  considerable  mucus.  Analysis 
showed:  total  acidity,  .18%;  free  HCl,  .09;  combined 
HCl,  .07.  The  motility  test  showed  the  presence  of  salol 
in  the  intestine  in  1  hour  and  25  minutes. 

Analysis  of  specimen  taken  July  3d  from  subject  "B."  In- 
gested at  1.39  p.m.  a  meal  as  detailed  above.  Withdrawn 
at  5.35  p.m.  Amount  of  chyme,  §ii.  Resorcin  test  showed 
the  presence  of  free  HCl. 

Tot.   acidity,    58,  or  .18%  by  Starch,  absent. 

wt.  Amylodextrin,  absent. 

Free  HCl,  26,  or  .09%  by  wt.  Erythrodextrin,  present. 

Comb'd  HCl,   20,  or  .07%  by  Maltose,  present. 

wt.  Peptones,  present. 

Tot.  HCl,  46,  or  .16%  by  wt.  Bile,  absent. 

Acid  salts,  12,  or  .04%  by  wt.  Mucus,    considerable  amount. 

Lactic  acid  (direct),    present.  Blood,  trace. 

The  K  I  absorption  test  was  not  made.  In  subject  "S"  the 
salol  test,  which  was  tried  by  way  of  control,  reacted  in  2  hours 
and  40  minutes.  The  urine  was  normal  in  amount  on  this  day. 
The  specific  gravity  at  various  times  was  1.024,  1.020,  1.022, 
and  1.006.    There  was  neither  sugar  nor  glycuronic  acid  present. 

July  4th. — Movillewas  reached  early  on  this  morning. 
By  7  a.m.,  the  Irish  passengers  had  been  sent  ashore, 
and  the  ship  was  on  its  way  to  Glasgow.  The  weather  was 
clear,  but  cold.     There  was  a  moderate  amount  of  rolling. 


354  SEASICKNESS 

Even  on  this  day,  some  of  the  subjective  phenomena  of 
seasickness  were  present. 

Protocol  13  shows  the  condition  of  the  circulation. 
Evidently  the  vaso-motor  system  showed  some  evidence  of 
recovery,  for  after  the  morning  cold  tub,  there  was  a  fair 
reaction,  which  persisted  for  at  least  half  an  hour.  How- 
ever, circulatory  insufficiency  appeared  immediately  when 
the  least  exertion  was  made,  such  as  attempting  to  ' '  pack 
up"  to  go  ashore. 

Although  inactivity  and  hot  weather  may  have  been  at 
times  responsible  for  the  conditions  represented  by  the 
figures  in  the  protocols,  yet  these  could  not  have  been  the 
chief  cause  of  the  circulatory  and  digestive  disturbances, 
as  particular  care  was  taken  to  see  that  the  subject  got 
sufficient  exercise  in  the  open  air;  and  moreover,  circula- 
tory depression  was  present  even  when  the  weather  was 
cold.  The  circulatoiy  conditions  on  this  day  must,  there- 
fore, be  attributed  in  part  to  the  failure  of  recovery  of  the 
vaso-motor  mechanism  from  the  previous  depression,  and 
in  part  to  the  effects  of  the  motion  of  the  boat,  and  the 
jarring  of  the  ship's  machinery.  It  is  interesting  to  note 
that  very  little  motion  or  vibration  suffices  to  protract  the 
vaso-motor  exhaustion,  or  rather  to  prevent  recovery  of  the 
mechanisms. 

At  6.58  a.m.,  an  Ewald  breakfast  was  given  subject 
"S"  by  way  of  control.  The  stomach  contents  were  re- 
moved at  8.10  a.m.  The  amount  of  chyme  was  ^iii,  with 
a  moderate  amount  of  mucus.  Analysis  showed:  total 
acidity,  .17%  by  wt. ;  free  HCl,  .11,  and  combined  HCl, 
.04. 

Analysis  of  specimen  taken  from  subject  "S"  July  4th.  Ewald 
breakfast  ingested  at  6.58  a.m.,  withdrawn  at  8.10  a.m. 
Amount  of  chyme,  ^iii.  Resorcin  test  showed  the  presence 
of  free  HCl. 

Tot.  acidity,  48,  or  .17%  by  wt.  Starch,  absent. 

Free  HCl,  32,  or  .11%  by  wt.  Amylodextrin,  trace. 

Comb'd  HCl,    12,  or  .04%  by  Erythrodextrin,  present. 

wt.  Maltose,  present. 

Tot.  HCl,   44,  or  .15%  by  wt.  Peptones,  present. 

Acid  salts,  4,  or  .01%  by  wt.  Bile,  absent. 

Mucus,  moderate  amount. 

Lactic  acid,  mere  trace.  Blood,  absent. 

Absorption  and  motility  tests  not  made. 


SEASICKNESS  855 

It  is  interesting  to  note  that  this  individual's  total 
acidity  and  free  HCl  were  considerably  reduced  as  com- 
pared with  his  normal  condition,  whilst  the  condition  of 
his  circulation  was  as  much  affected  as  that  of  subject 
"B,"  as  shown  in  protocols  11,  11a,  12,  and  12a.  The 
circulatory  mechanisms  of  subject  "S"  also  showed  on 
the  slightest  effort,  marked  exhaustion,  which  lying  down 
did  not  seem  to  relieve  as  promptly  as  it  did  in  the  case 
of  subject  "B."  From  extensive  and  repeated  observa- 
tions of  these  two  subjects,  the  conclusion  was  reached 
that  one  of  them,  viz.,  subject  "B,"  the  one  on  whom  the 
observations  were  chiefly  made  during  this  voyage,  pos- 
sessed a  keen  and  effective  vaso-motor  apparatus  and  a 
comparatively  weak  and  irritable  heart,  whilst  the  other 
(subject  "S")  had  a  strong  and  efficient  heart  muscle, 
but  a  comparatively  feeble  vaso-motor  mechanism.  These 
facts  were  apparent  in  other  ways.  Thus  in  subject  "B" 
cold  air,  or  cold  bathing  had  always  a  wonderful  effect  in 
bracing  the  circulation,  except  when  the  neuro-vascular 
mechanism  was  in  a  state  of  exhaustion  from  constant 
overstimulation,  as  occurred  at  times  during  the  voyage. 
In  subject  "S"  the  effect  of  cold  was  to  produce  a  chill, 
with  blueness  of  the  surface,  and  without  any  evidence  of 
the  tonic  hypersemia  of  the  skin  such  as  was  always  ob- 
served in  subject  "B."  The  inefficiency  of  the  neuro- 
vascular mechanism  in  this  individual  "S"  accounts  for 
the  fact  that  in  him,  as  compared  with  subject  "B, "  there 
was  a  less  marked  rise  of  blood-pressure  noted  upon  lying 
down,  although  the  pulse-rate  fell,  as  in  subject  "B,"  to 
the  normal.  See  protocols  11,  11a,  12,  and  12a.  It  ap- 
pears that  this  difference  in  the  neuro-vascular  mechanisms 
was  in  part  at  least,  what  rendered  the  one  with  the  less 
efficient  vaso-motor  apparatus  less  susceptible  to  the  effects 
of  rotation  and  aural  irrigation,  and  to  galvanism  over 
the  mastoid  areas.  The  effects  of  prolonged  constant  irri- 
tation of  the  medullary  centres,  such  as  occurs  in  condi- 
tions obtaining  at  sea,  were  sufficient  to  beget  vaso-motor 
exhaustion,  and  when  the  latter  supervened  its  effect  upon 
the  circulation  was  very  marked,  causing  an  almost  con- 
tinuous overlapping  of  the  blood-pressure  and  pulse-rate 
curves.  This  difference  in  the  sensitiveness  of  the  neuro- 
vascular mechanism  of  different  individuals,  coupled  with 


356  SEASICKNESS 

the  varying  sensitiveness  of  the  labyrinthine  receptors, 
throws  considerable  light  upon  the  varying  susceptibility 
of  individuals  to  seasickness.  The  considerable  rise  in 
blood-pressure  that,  upon  lying  down,  constantly  occurred 
in  subject  "B"  was  due,  no  doubt,  to  increased  blood- 
supply  in  the  medullary  centres  procured,  in  the  first  in- 
stance, by  recumbency  which  aided  the  return  flow  to  the 
right  heart.  The  improved  circulation  in  the  medulla, 
w^ith  the  increased  supply  of  nutrition,  so  enhanced  the 
metabolic  processes  in  the  centres,  that  a  certain  amount 
of  vaso-motor  tonus  resulted.  Hence,  in  looking  over  the 
protocols,  it  will  be  seen  that  frequently  the  radial  artery 
is  in  a  more  or  less  firm  state  of  contraction  with  the  sub- 
ject in  recumbency. 

At  8.15  p.m.  the  passengers  were  landed  at  Stobcross 
Quay,  Glasgow.  The  condition  of  the  circulation  imme- 
diately improved,  as  shown  in  protocol  13.  There  was 
evidence  of  improved  vaso-motor  tonus,  though  of  course 
all  the  effects  of  vaso-motor  exhaustion  had  not  worn  off. 


CHAPTER  XXVI 
STUDIES  IN  SEASICKNESS    (Continued) 

July  5th. — The  general  improvement  of  the  circulation 
on  shore  is  further  shown  in  protocol  14.  Improved  vaso- 
motor tonus  was  manifested  by  the  manner  in  which  the 
circulation  was  maintained  in  the  erect  posture  without 
undue  overaction  on  the  part  of  the  heart.  It  was  ap- 
parent, however,  that  the  recovery  of  the  vaso-motor 
mechanism  was  as  yet  by  no  means  complete.  At  7.58 
p.m. ,  the  steamship  Tiger ^  of  Duke's  Line,  bound  for  Dub- 
lin, was  boarded.  Even  before  the  boat  started,  there  was 
evidence  of  loss  of  vaso-motor  tone,  due  in  part  to  failure 
of  recovery  from  the  effects  of  the  ocean  voyage,  and  in 
part  to  the  exertions  made  to  catch  the  boat.  Moreover, 
the  cabin  was  rather  warm.  When  the  boat  started,  sub- 
jective phenomena  soon  appeared.  The ' '  lump-sensation' ' 
was  in  evidence,  with  fulness  in  the  head,  occipital  head- 
ache, fulness  in  the  ears,  parsesthesiae  of  the  scalp,  irrita- 
bility of  temper,  worrisomeness,  etc.  The  condition  of 
the  circulation  during  the  journey  is  shown  in  protocol  14a. 
There  was  evidence  of  loss  of  vaso-motor  tone.  These  ob- 
servations show  that  after  seasickness,  the  recovery  of  the 
circulation  takes  place  slowly.  They  also  show  that  it  re- 
quires very  little  in  the  way  of  motion  or  jolting  to  cause 
a  return  of  the  malady  with  its  vaso-motor  exhaustion, 
and  circulatory  depression.  Here  it  may  be  remarked  that 
the  vestibulo-cerebellar  mechanisms  of  an  individual  may 
become  accustomed  to  the  motions  of  a  large  ship,  so  that 
going  to  sea  on  that  particular  ship  or  perhaps  on  another 
ship  of  equal  size,  would  not  occasion  seasickness,  whilst 
if  such  an  individual,  believing  himself  immune,  were  to 
ship  in  a  smaller  vessel,  the  difference  in  the  rate  and 
rhythm  of  the  movements  would  be  sufficient  to  cause  pro- 
found illness.  And  such  was  actually  the  experience  of  a 
sailor  who,  upon  first  going  to  sea,  shipped  in  a  large 
boat.     He  went  to  sea  for  fully  six  months  before  he  ' '  got 

357 


358  SEASICKNESS 

over  being  sick."  After  remaining  with  the  same  ship 
for  fifteen  years,  he  made  a  change  and,  shipping  in  a 
smaller  vessel,  found  that  he  became  seasick  every  time 
he  went  to  sea.  It  took  him  several  months  for  his  ves- 
tibulo-cerebellar  mechanisms  to  become  attmied  to  the 
movements  of  the  second  vessel. 

During  this  trip  the  weather  was  fair,  but  the  boat 
being  very  much  smaller  than  the  Caledonia,  and  the  rate 
and  range  of  its  movements  so  different,  very  little 
motion  showed  marked  effects  upon  the  labyrinthine 
mechanisms.  Moreover,  the  jolting  and  vibration  due  to 
the  machinery  of  the  boat,  were  more  in  evidence. 

The  K  I  absorption  test  was  tried  at  9.15  p.m.,  and 
iodine  was  found  in  the  saliva  at  10.24  p.m. 

On  July  6th,  at  7  a.m.,  the  North  Wall,  Dublin,  was 
reached,  the  condition  of  the  circulation  being  as  shown 
in  protocol  14a.  There  is  evidence  of  vaso-motor  fatigue 
even  after  a  fair  night's  rest. 

July  10th. — On  this  day  a  trip  from  Dublin  to  South- 
ampton was  commenced  on  board  the  steamship  Lady 
Wolseley,  of  the  British  and  Irish  Steam  Packet  Co.  The 
boat  started  at  4.54  p.m.  During  the  few  days  spent  in 
Dublin,  subject  "B"  indulged  rather  freely  in  alcoholic 
liquors.  His  chief  drink  was  Bass's  ale  and  Guinness's 
stout,  although  occasionally  he  took  whiskey  and  soda. 
Up  to  this  time  no  alcohol  had  been  taken  by  him  for 
over  a  year.  Before  boarding  the  boat  he  had  taken,  dur- 
ing the  day,  eight  bottles  of  stout,  and  one  whiskey  and 
soda.  Plenty  of  time  was  allowed  to  prepare  for  the 
journey,  so  that  there  should  be  no  hurry,  which  might 
mar  the  observations  on  the  blood-pressure.  Just  as  the 
boat  started,  the  circulation  showed  a  marked  degree  of 
depression,  as  indicated  in  protocol  15a.  This  depression 
was  chiefly  the  result  of  vaso-motor  (and  perhaps  cardiac) 
inefficiency,  due,  in  part  perhaps,  to  the  effects  of  alcohol. 
It  is  worthy  of  note  that  the  pulse-rate  did  not  fall  when 
the  subject  lay  down.  This  shows  well  the  action  of  alco- 
hol upon  the  cardio-vascular  mechanism,  and  wherein  it 
differs  from  the  effects  of  mere  fatigue,  in  which  the  heart 
enjoys  considerable  rest  when  the  subject  is  in  recumbency, 
a  thing  not  permitted  by  an  excess  of  alcohol  circulating 
in  the  blood.     The  inference  is,  that  whilst  within  limits. 


SEASICKNESS  859 

exertion  may  be  a  good  thing  for  the  heart,  by  stimula- 
ting the  nutrition  of  its  muscle,  the  kind  of  work  thrown 
upon  the  heart  by  overindulgence  in  alcohol  is  never 
beneficial,  but  the  reverse,  as  the  rapid  rate,  even  when 
resting  in  recumbency,  does  not  permit  sufficient  time  dur- 
ing diastole  for  the  processes  of  proper  metabolic  inter- 
change. These  things,  in  addition  to  the  direct  effect  of 
alcohol  upon  the  heart- structure  itself,  lead  to  rapid  de- 
terioration and  degeneration  of  the  muscle. 

During  the  early  evening  the  water  was  calm,  but 
about  9  p.m.  the  boat  rolled  and  pitched  somewhat. 
The  "lump-sensation' '  in  the  stomach  reappeared  and  with 
it  dizziness,  increased  saliva,  etc.  The  subject  began  to 
feel  very  tired,  as  people  will  who  overindulge  in  alcohol. 
It  was  a  great  relief  to  lie  down. 

The  circulation  during  this  period  of  the  journey 
showed  fatigue  of  the  whole  cardio-vascular  mechanism. 
The  respirations  were  24,  with  the  subject  feeling  sleepy 
and  very  nervous. 

July  11th. — During  the  night  the  weather  became  very 
rough.  The  ship  rolled  and  pitched  in  an  extraordinary 
fashion.  Everything  in  the  stateroom  was  hurled  about, 
so  that  demoralization  and  disorder  prevailed.  When  sub- 
ject "B"  awoke  at  4  a.m.,  and  whilst  he  still  lay  in 
bed,  the  motion  of  the  ship  made  him  dizzy  and  sick.  He 
was  lying  with  his  head  toward  the  bow,  and  with  the 
right  side  next  to  the  water  in  an  outside  berth.  The 
"lump-sensation"  in  the  stomach  and  throat  was  so 
marked,  that  he  constantly  kept  "swallowing  to  keep  it 
down."  He  experienced,  in  this  position,  a  slight  ache 
in  the  muscles  attached  to  the  occiput  upon  the  right  side. 
Any  concentration  or  mental  effort  was  disagreeable,  and 
tended  to  make  him  sick.  The  subject  lay  upon  either 
side  to  see  if  the  position  would  have  any  effect  in  allevi- 
ating or  aggravating  his  condition.  It  was  noted  that 
although  lying  upon  the  side  made  him  feel  worse  than 
lying  on  the  back,  it  did  not  make  any  material  difference 
upon  which  side  he  lay. 

By  8.15  a.m.,  the  subject  was  suffering  from  all  the 
effects  of  fully  developed  seasickness.  The  "Ixmap-sensa- 
tion"  in  the  stomach  was  much  in  evidence.  The  stom- 
ach-tube was  introduced,  but  nothing  returned.     Water, 


860  SEASICKNESS 

|vi,  was  now  swallowed  and  the  tube  reintroduced.  A  mass 
of  thick  tenacious  mucus  was  removed  and  with  it  some 
fresh  blood.  During  all  this  time  the  blood-pressure  was 
well  maintained,  partly  on  account  of  the  muscular  efforts 
made  in  balancing.  At  7.80  a.m.  an  Ewald  breakfast  was 
given,  after  which  the  subject  lay  in  bed,  in  order  that  he 
might  retain  it.  During  this  time  the  ship  continued  to 
loll  and  pitch  excessively.  The  subject  experienced  all 
the  subjective  phenomena  of  seasickness,  with  lump-sensa- 
tion in  the  stomach,  headache,  nausea,  increased  saliva- 
tion, psychic  and  motor  depression,  and  that  dreadful 
"dolor  cerebri"  familiar  to  all  who  have  suffered  from  sea- 
sickness. He  felt  and  acted  as  though  he  were  being 
dragged  to  execution  when  told  that  it  was  time  to  remove 
the  stomach  contents,  which  was  done  at  8.80  a.m.  It  was 
a  difficult  matter  to  get  the  chyme  through  the  tube,  which 
was  at  first  blocked  by  thick  mucus  with  blood  admixed. 
After  much  ado,  3iv  were  removed.  Then  the  stomach 
was  irrigated,  and  more  mucus,  with  a  little  blood,  was  re- 
moved. The  subject  stated  that  his  stomach  felt  better 
after  the  irrigation.  Analysis  after  the  Ewald  meal 
showed:  total  acidity,  .06%  by  wt.,  freeHCl  absent,  com- 
bined HCl,  .02. 

In  subject  "S,"  who  vomited  the  contents  of  his  rest- 
ing stomach,  analysis  showed :  total  acidity,  .04%  by  wt., 
with  free  HCl  absent. 

Analysis  of  specimen  taken  July  11th  from  subject  "B." 
Ingested  at  7.30  a.m.,  an  Ewald  breakfast.  Withdrawn  at 
8.30  a.m. 

Amount  of  chyme,  ?iv.  Coagulating  enzymes  (chymo- 

Reaction  (litmus) ,  faintly  acid.  sin,  etc.),  diminished  or  ab- 

Free  HCl  (resorcin),  absent.  sent. 

Tot.  acidity,  18, or  .06%  by  wt.  Coagulating  zymogen  (chymo- 
Free  HCl,  absent.  sinogen),  diminished  or  ab- 

Combined  HCl,  12,  or.02%by  sent. 

wt.  Peptonizing  enzymes  (pepsin), 

Acid  salts,  .  diminished  or  absent. 

Peptonizing  zymogen  (pepsin- 
Lactic   acid    (direct),    absent  ogen),    diminished    or    ab- 

or  mere  trace.  sent. 

Starch,  absent.  Bile,  absent. 

Amylodextrin,  trace.  Mucus,  considerable  excess. 

Erythrodextrin,  present.  Blood,  present. 

Achroodextrin,  present.  Absorption  and  motility  tegts 

Maltose,  present.  not  made. 


SEASICKNESS  361 

Analysis  of  specimen  taken  July  11th  from  subject  "S." 
Contents  of  resting  stomach  vomited  during  seasickness. 

Reaction,     faintly    acid     (lit-  Lactic  acid  (direct),  absent. 

mus).  Starch,  absent. 

Free  HCl,  absent  (resorcin).  Amylodextrin,  absent. 

Tot.  acidity,  12,  or. 04% by  wt.  Erythrodextrin,  absent. 

Free  HCI,  absent.  Achroodextrin,  absent. 

Combined  HCl,  absent.  Maltose,  absent. 

The  amount  of  material  vomited  was  about  |ii,  and  consisted 
mainly  of  mucus. 

In  the  early  afternoon  the  sea  became  calm,  and  both 
subjects,  after  lying  down  all  through  the  forenoon,  were 
able  to  appear  at  table. 

The  condition  of  the  circulation  in  subject  ' '  B "  dur- 
ing this  rough  tilt  is  shown  in  protocol  15b.  In  recum- 
bency the  blood-pressure  was  higher  than  usual,  due  in 
part  no  doubt,  to  the  muscular  action  incidental  to  toss- 
ing about  in  bed.  In  the  erect  posture  it  was  difficult  to 
determine  the  true  state  of  the  circulation,  on  account  of 
the  extreme  rolling  and  pitching.  Accurate  manipulation 
of  the  instruments  was  hampered,  whilst  efforts  at  balan- 
cing caused  sudden  and  frequent  variations  in  blood- 
pressure.  The  blood-pressure  figures  must  therefore  be 
understood  as  representing  in  great  part  the  effects  of 
muscular  exertion.  At  this  juncture  it  was  evident  that  the 
best  time  to  study  the  circulation  in  seasickness  is  not  dur- 
ing rough  weather,  but  rather  under  milder  conditions 
and  in  the  lighter  phases  of  the  malady.  At  3.25  p.m. 
Falmouth  was  reached.  A  pleasant  stroll  was  enjoyed 
during  a  peaceful  afternoon.  The  effects  upon  the  circu- 
lation are  shown  in  protocol  15b.  There  was  improvement 
in  the  vaso-motor  tone  as  evidenced  by  the  well-maintained 
pressure  in  the  erect  posture  with  lowered,  regular  pulse- 
rate.  The  subject  slept  on  the  boat  alongside  Falmouth 
pier,  and  passed  a  fairly  good  night,  but  was  disturbed 
early  in  the  morning  by  the  donkey  engine  unloading 
cargo. 

July  12th. — At  9.18  a.m.  the  boat  started  for 
Plymouth.  The  weather  was  mild,  and  the  boat  quite 
steady.  The  subject  felt  well,  and  experienced  little  dis- 
comfort, excepting  a  slight  occipital  headache.  The  ma- 
chinery,   however,   was    responsible    for    much    jolting. 


362  SEASICKNESS 

Pl3miouthwas  reached  about  3  p.m.  During  the  after- 
noon, the  subject  strolled  about  the  ancient  town.  At 
6  p.m.  the  boat  sailed  for  Southampton.  The  weather 
was  calm,  and  beyond  a  slight  occipital  headache,  with  a 
little  congestion  of  the  face  and  head,  the  subject  felt  no 
disagreeable  symptoms. 

At  7.38  p.m.,  after  dinner,  the  absorption  test  was  tried 
and  iodin  was  found  in  the  saliva  after  2  hours  and  7 
minutes.  During  this  test  the  boat  rolled  and  pitched 
somewhat,  and  subject  "B"  felt  the  "lump-sensation" 
and  experienced  a  slight  fulness  in  the  head.  He  also  had 
a  transient  attack  of  dizziness.  The  circulation  was  fairly 
well  maintained,  as  shown  in  protocol  15c.  The  subject 
had  moderately  indulged  in  ale  during  the  evening. 

July  13th. — On  awaking,  the  subject  experienced 
slight  symptoms  of  indigestion.  The  circulation  showed 
evident  signs  of  recovery,  as  seen  in  protocol  15d.  The 
overlapping  of  the  blood-pressure  and  pulse-rate  curves 
upon  first  standing  up,  as  seen  at  5.57  a.m.,  illustrates  an 
interesting  feature  in  the  physiology  of  the  vaso-motor 
system.  When  an  individual  makes  a  muscular  effort 
without  thorough  psychic  concentration,  the  neuro-vascular 
apparatus  may  be  slow  in  responding  to  the  demands  of 
the  body  for  higher  blood-pressure.  The  result  is  that  the 
heart  has  to  make  up  with  increased  rate  for  the  tardy 
vaso-motor  action.  It  has  frequently  happened  with  sub- 
ject "B"  that  in  walking  up  a  series  of  flights  of  stairs 
in  a  half-hearted  way,  but  nevertheless  at  a  fair  pace  and 
without  stopping,  the  heart- rate  was  enormously  increased, 
and  the  breathing  deep  and  laboured,  whereas,  when  he 
roused  himself  thoroughly  and  bent  himself  to  the  task 
of  running  up  the  same  stairs  at  a  brisk  trot,  lifting  his 
feet  neatly  and  giving  free  play  to  the  muscles  of  his  whole 
body,  the  heart-rate  was  only  moderately  increased  and 
the  auxiliary  circulatory  function  of  the  resi)iratory  mech- 
anism was  not  so  much  invoked.  Tardiness  or  lethargy 
on  the  part  of  the  neuro-vascular  mechanism  is  common 
in  many  diseased  conditions.  It  is  the  direct  result  of 
tcjxfemia  in  infectious  diseases,  and  it  is  to  its  effects  in 
counteracting  this  lethargy  of  the  reflexes  that  cold  bath- 
ing with  friction  owes  its  value  in  these  conditions. 

Lethargy  of  the  vaso-motor  mechanism,  and  of  the  re- 


SEASldKNESS  863 

flexes  generally,  is  also  met  with  in  other  than  diseased 
conditions,  e.g.,  in  the  waning  period  of  the  athlete's 
career  when  he  has  to  "warm  up"  before  he  can  attain  his 
normal  speed  and  accuracy  of  movement. 

As  the  subject  dressed,  he  felt  weak  and  nauseated. 
His  condition  was  attributed  more  to  the  stuffy  cabin  and 
the  ale  he  had  taken  on  the  previous  night,  than  to  the 
effect  of  the  boat's  motion.  As  time  wore  on,  the  feeling 
passed  off,  and  he  felt  very  well  as  the  boat  glided  up 
Southampton  Water.  At  6.10  a.m.,  Southampton  was 
reached. 

At  11.50  p.m.,  the  first  of  a  series  of  trips  upon  the 
steamship  Soiithivester^i^  running  between  Southampton 
and  Cherbourg,  was  commenced.  The  English  Channel 
has  a  world-wide  reputation  for  causing  seasickness, 
and  it  was  intended  to  make  the  most  of  every  oppor- 
tunity. 

July  14th. — At  12.24  a.m.  the  boat  started.  The  con- 
dition of  the  circulation  before  and  after  the  start  is 
shown  in  protocol  16a.  There  was  evidence  of  recovery 
of  the  circulation  from  the  effects  of  the  previous  journeys. 
The  weather  was  mild,  and  the  water  in  a  still  calm.  The 
subject's  berth  was  situated  about  amidships,  and  trans- 
verse to  the  long  axis  in  such  a  manner,  that  his  head  was 
located  near  the  middle  of  the  boat,  with  his  feet  directed 
to  the  port  side.  On  awakening  at  6.30  a.m.,  the  boat 
was  pitching  furiously,  with  a  short,  snappy  motion  com- 
bined with  a  slight  spiral  twist.  The  subject  woke  up 
with  all  the  symptoms  of  seasickness,  viz.,  "lump-sensa- 
tion" in  the  stomach,  with  nausea  and  increased  saliva- 
tion. He  was  very  nervous  and  apprehensive.  Lying  on  the 
back  gave  most  relief,  whilst  lying  upon  either  side  seemed 
to  make  him  sicker.  This  will  be  readily  understood  when 
it  is  remembered  that  the  chief  motion  of  the  boat  con- 
sisted in  pitching,  which  affected  chiefly  the  horizontal 
semicircular  canals  in  the  position  in  which  he  lay. 

It  will  be  remembered  that  the  sheep,  with  the  vestib- 
ular nerve  divided,  lies  upon  the  side  of  operation.  In 
this  position  the  muscles  on  that  side  are  relaxed,  and  re- 
ceive little  or  no  cerebellar  tonus  innervation.  Since  these 
muscles  are  related  to  the  labyrinth  on  the  opposite  side, 
i.e.,  of  the  sound  side,  the  vestibular  mechanism  on  that 


864  SEASICfcNESS 

side  may  be  said  to  be  quiescent  and  at  rest.  The  conse- 
quence is,  that  the  muscles  of  the  sound  side  require  little 
or  no  vestibulo-cerebellar  tonus  to  counterbalance  their  re- 
laxed opponents.  Practically  no  demand  for  tonus  im- 
pulses is  therefore  made  on  the  peripheral  vestibular  ap- 
paratus on  the  side  related  to  these  muscles,  viz.,  the  side 
on  which  the  vestibular  nerve  has  been  divided.  The  re- 
sult is,  that  the  animal  can  maintain  this  position  with- 
out suffering  the  torments  of  vertigo.  In  any  other  posi- 
tion there  would  be  a  demand  for  vestibular  tonus- impulses 
from  the  side  of  operation  and  failure  to  supply  them 
would  effect  a  break  in  the  balance,  with  disturbances  of 
equilibrium,  vertigo,  nystagmus,  etc. 

The  case  of  subject  "B"  is  somewhat  analogous. 
Turning  upon  one  side  sets  at  rest  the  labyrinth  of  the 
opposite  side.  Under  the  influence  of  active  stimulation 
of  the  ampullary  receptors  on  either  side  by  means  of  the 
boat's  motion,  this  position  is  by  no  means  one  of  stable 
equilibrium,  for  as  the  boat  pitches,  more  or  less  reflex 
muscular  activity  is  evoked,  with  resulting  tendencies  to 
disturb  the  equilibrium.  The  fact  that  the  muscles  of 
one  side  have  a  tendency  to  be  relaxed  and  at  rest  by  lying 
on  that  side,  whilst  their  opponents  under  the  conditions 
of  active  labyrinthine  stimulation  are  not  permitted  to  be 
at  rest,  only  tends  all  the  more  to  cause  a  disturbance  of 
balance  between  the  opposing  muscles  on  either  side. 
Under  these  circumstances,  the  effect  of  the  boat's  motion 
is  to  keep  up  a  constant  disturbance  of  the  vestibulo- 
cerebellar balanced  mechanisms,  with  resulting  discomfort 
and  distress  to  the  individual. 

At  7. 15  a.m. ,  the  tube  was  passed,  but  nothing  was  re- 
covered from  the  stomach.  Irrigation  of  that  organ  was 
then  practised,  and  a  quantity  of  thick  mucus,  mixed  with 
some  fresh  blood,  was  removed.  The  stomach  felt  better 
after  irrigation.  The  condition  of  the  circulation  during 
this  period  is  shown  in  protocol  10a.  The  blood-pressure 
was  well  maintained,  but  this  was  in  part  due  to  the  mus- 
cular efforts  of  balancing.  The  vaso-motor  tone  was  still 
deficient,  as  evidenced  by  the  increased  pulse-rate  neces- 
sary U)  maintain  a  fair  blood-pressure.  At  7.20  a.m., 
the  boat  arrived  at  Cherbourg. 


SEASICKNESS  365 

On  the  evening  of  July  14th  the  absorption  test  was 
tried  on  shore  after  dinner.  The  saliva  reacted  for  iodin 
in  1  hour  and  10  minutes.  The  subject  "B"  had  some 
symptoms  of  indigestion,  and  was  very  nervous.  The 
night  was  close,  and  he  slept  but  little. 

July  15th. — After  dinner  the  absorption  test  was  again 
tried.  Iodin  was  found  in  the  saliva  in  1  hour  and  35 
minutes. 

July  16th. — On  this  day  an  attempt  was  made  to  study 
the  immediate  effect  which  travelling  on  a  moving  train 
has  upon  the  circulation.  All  that  could  be  ascertained 
with  any  certainty,  was  that  the  peripheral  blood-vessels 
were  constricted  at  times,  and  the  blood-pressure  raised. 
Such  results  as  could  be  fairly  ascertained  are  shown  in 
protocol  16b. 

July  17th. — On  this  day  the  absorption  test  showed 
the  presence  of  iodin  in  the  saliva  in  23  minutes. 

July  18th. — At  2  p.m.  lunch  was  taken,  consisting  of 
cold  roast  beef,  potatoes,  vegetables,  bread  and  butter,  and 
coffee  with  milk  and  sugar.  At  7.20  p.m.  the  stomach 
contents  were  removed  and  the  stomach  thoroughly  irri- 
gated. At  7.50  p.m.  an  Ewald  test  meal  was  given. 
The  absorption  test  was  tried,  and  iodin  appeared  in  the 
saliva  in  10  minutes.  With  the  motility  test,  no  evidence 
of  salicyluric  acid  was  found  in  the  urine  as  late  as  9.22 
p.m.  At  9.05  p.m.  the  stomach  contents  were  with- 
drawn. The  amount  of  chyme  removed  was  $11.  Analysis 
showed  for  the  first  specimen,  i.e.,  the  one  taken  at  7.20 
p.m.,  or  5  hours  and  20  minutes  after  a  meat  lunch,  total 
acidity,  .219%  by  wt. ;  freeHCl,  .138;  combinedHCl,  .07; 
and  for  the  specimen  after  the  Ewald  meal :  total  acidity, 
.138%;  freeHCl,  .080;  combinedHCl,  .051.  It  was  found 
that  notwithstanding  the  irrigation  some  meat  from  the 
midday  meal  had  remained  in  the  stomach  during  the 
Ewald  meal. 

A  test  meal  was  given  subject  "S"  by  way  of  control. 
In  his  case  the  analysis  showed:  total  acidity,  .299%  by 
wt. ;  freeHCl,  .21;  combinedHCl,  .07,  with  the  absorption 
test  showing  the  presence  of  iodin  in  the  saliva  in  15 
minutes.     The  motility  test  was  not  tried. 


see 


SEASICKNESS 


Analysis  of  specimen  taken  July  18th  from  subject  "B. "  In- 
gested at  2  p.m.,  lunch  consisting  of  cold  meat,  lettuce, 
carrots,  potatoes,  coffee  with  milk  and  sugar,  and  bread 
with  butter.  Withdrawn  at  7.20  p.m.  Amount  of  chyme, 
3iv.     Resorcin  test  showed  the  presence  of  free  HCl. 


Tot.  acidity,  60,  or  .219%  by 

wt. 
Free  HCl,  38,  or  .13%  by  wt. 
Comb'd  HCl,    20,  or  .07%  by 

wt. 
Tot.  HCl,  58,  or  .20%  by  wt. 
Acid  salts,  2,  or  .007%  by  wt. 


Starch,  absent. 
Amylodextrin,  absent. 
Erythrodextrin,  absent. 
Achroodextrin,  absent. 
Maltose,  trace. 
Peptones,  present. 
Bile,  absent. 
Mucus,  minute  amount. 
Blood,  absent. 


Lactic  acid  (direct),    present 

Absorption  and  motility  tests  not  made. 

Note.  The  chyme  contained  particles  of  lettuce  and  carrots 
and  some  small  pieces  of  meat,  but  otherwise  it  was  fairly  nor- 
mal. 


Analysis  of  specimen  taken  July  18th  from  subject  "B."  In- 
gested at  7.50  p.m.  an  Ewald  test  meal.  Withdrawn  at  9.05 
p.m.  Amount  of  chyme,  lii.  Resorcin  test  showed  the 
presence  of  free  HCl. 


Tot.  acidity,  38,  or  .13%  by  wt. 
Free  HCl.  22,  or  .08%  by  wt. 
Comb'd  HCl,   36,  or  .13%  by 

wt. 
Acid  salts,  2,  or  .007%  by  wt. 

Lactic  acid  (direct),  trace. 
Starch,  absent. 


Amylodextrin,  absent. 
Erythrodextrin,  present. 
Achroodextrin,  present. 
Maltose,  present. 
Peptones,  present. 
Bile,  absent. 
Mucus,  very  little. 
Blood,  absent. 


Analysis  of  specimen  taken  July  18th  from  subject  "S."  In- 
gested at  7.50  p.m.  an  Ewald  meal.  Withdrawn  at  9  p.m. 
Amount  of  chyme,  ?iii.  Resorcin  test  showed  the  presence 
of  free  HCl. 


Tot.  acidity,   82,  or  .299%,  by 

wt. 
Free  HCl.  58,  or  .211%o  by  wt. 
Comb'd  HCl,  22,  or  .077%,  by 

wt. 
Tot.  HCl,  80,  or  .288%  by  wt. 
Acid  salts,  2,  or  .007%  by  wt. 

Lactic  acid  (direct),  trace. 


Starch,  absent. 
Amylodextrin,  trace. 
Erythrodextrin,  present. 
Achroodextrin,  present. 
Maltose,  present. 
Peptones,  present. 
Bile,  absent. 
Mucus,  very  little. 
Blood,  absent. 


SEASICKNESS  S67 

July  19th. — The  condition  of  the  circulation  on  this 
day  is  shown  in  protocol  17.  The  vaso-motor  system  had 
evidently  recovered  from  the  effects  of  the  sea. 

July  20th. — On  this  day,  a  trip  was  made  on  the 
steamship  Cygne  from  Carteret  to  Gorey  in  Jersey,  Chan- 
nel Islands.  The  weather  was  pleasant,  but  there  was  a 
considerable  roll  on  the  MancJie,  and  many  passengers 
were  made  ill.  An  Ewaldtest  meal  was  given  on  the  fast- 
ing stomach  to  subjects  "  B  "  and  "  S. "  Both  were  seated 
in  the  hot  sun,  fairly  well  amidships,  where  all  sorts  of 
disagreeable  sights  and  odours  prevailed.  The  boat  rolled 
and  pitched  very  much.  Subject  ''B"  experienced  only 
the  faintest  symptoms  of  seasickness. 

The  amount  of  chyme  recovered  from  the  test  meal 
given  subject  "B"  was  riii.  Analysis  showed:  total 
acidity,  .146%by  wt. ;  free  HCl,  .06;  combined  HCl,  .06. 
A.  trace  of  blood  was  found  in  the  chyme.  The  absorption 
test  showed  the  presence  of  iodin  in  the  saliva  in  15  min- 
utes. The  salol  test  showed  the  presence  of  salicyluric 
acid  in  the  urine  in  85  minutes.  There  was  reason  to 
suspect  that  this  early  reaction  was  the  result  of  the  salol 
taken  on  the  previous  evening.  The  stronger  reaction  ap- 
peared in  1  hour  20  minutes.  The  amount  of  chyme  re- 
covered after  the  test  meal  given  to  subject  "S"  was  fiii. 
Analysis  showed :  total  acidity,  .146;  free  HCl,  .153;  com- 
bined HCl,  .109.  The  absorption  test  showed  a  positive 
reaction  in  14  minutes.  The  salol  motility  test  reacted 
in  1  hour  and  19  minutes. 


Analysis  of  specimen  taken  July  20th  on  the  Cygne  from  subject 
"B."  Ingested  at  8.14  a.m.  an  Ewald  breakfast.  With- 
drawn at  9.20  a.m.  Amount  of  chyme,  siii.  Resorcin  test 
showed  a  feeble  reaction  for  free  HCl. 

Tot.  acidity,  40,  or .  1469o  by  wt.  Amylodextrin,  absent. 

Free  HCl,  18,  or  .065%  by  wt.  Erythrodextrin,  present. 

Comb'd  HCl,   18,  or  .065%  by  Achroodextrin,  present. 

wt.  Maltose,  present. 

Tot.  HCl,  36,  or  .130%  by  wt.  Peptonizing   and    coagulating 
Acid  salts,  4,  or  .014%  by  wt.  enzymes,  normal. 

Peptones,  present. 

Lactic     acid    (direct),     faint  Bile,  absent. 

trace.  Mucus,  considerable  amount. 

Starch,  absent.  Blood,  trace. 


368  SEASICKNESS 

Analysis  of  specimen  taken  on  July  20th  on  the  Cygne  from 
subject  "S."  Ingested  at  8.16  a.m.  an  Ewald  breakfast. 
Withdrawn  at  9.25  a.m.  Amount  of  chyme,  liii.  Resorcin 
test  showed  the  presence  of  free  HCl. 

Tot.  acidity,  72,  or  .262%  by  Peptonizing    and   coagulating 

wt.  enzymes,  normal. 

Free   HCl,    42,    or  .153%   by  Starch,  absent. 

wt.  Amylodextrin,  present. 

Comb'd  HCl,  30,  or  .109%  by  Erythrodextrin,  present. 

wt.  Achroodextrin,  present. 

Tot.    HCl,    72,   or   .262%    by  Maltose,  present. 

wt.  Peptones,  present. 

Acid  salts,  .  Bile,  absent. 

Lactic  acid  (direct),  absent  or  Mucus,  very  little. 

faint  trace.  Blood,   trace. 

Note.  A  little  gross  blood  appeared  during  the  manipulations 
in  evacuating  the  stomach  contents.  The  blood  was  kept  away 
as  well  as  possible  from  the  chyme. 

A  comparison  of  the  analysis  from  the  test  meals  taken 
on  the  Cygne,  and  those  taken  on  the  previous  evening 
shows  that  in  the  matter  of  acidity  in  general  there  was 
not  much  difference.  Evidently  both  subjects  had  devel- 
oped a  certain  amount  of  immunity  for  seasickness.  It 
should  be  mentioned  that  the  Cygne  was  in  size  and  other 
respects  very  similar  to  the  boats  on  which  the  subjects 
had  been  recently  travelling. 

The  condition  of  the  circulation  during  this  trip  is 
shown  in  protocol  17.  Evidently  the  vaso-motor  system 
was  in  keen  working  order.  A  fair  amount  of  muscular 
action,  however,  was  necessitated  by  the  motion  of  the 
boat,  and  moreover  the  observations  upon  blood-pressure 
were  taken  in  the  open  air. 

July  22d. — On  this  day  a  trip  was  made  in  the  fish- 
ing smack  Quatre  Freres.  This  was  a  sail-boat,  and  of 
course  very  much  smaller  than  the  boats  in  which  the 
subjects  had  been  recently  travelling.  From  the  very  start 
it  rolled  and  twisted  and  pitched  in  a  fearful  manner. 
Test  meals  were  given  to  subjects  "  B  "  and  "  S, "  but  "  S  " 
vomited  his  meal  26  minutes  after  its  ingestion.  It  was 
only  by  hugging  the  floor  of  the  cabin  where  he  had 
wedged  himself  in  between  some  cleats  and  the  side  of  the 
vessel,  that  subject  "B"  succeeded  in  retaining  his  meal 
for  the  accustomed  hour.      The  day  was  clear,  but  the 


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SEASICKNESS  869 

Manclie  was  living  up  to  its  reputation.  On  this  occasion 
subject  "B"  experienced  all  the  horrors  of  seasickness  in 
its  most  aggravated  form.  The  odour  of  the  cabin,  not  too 
wholesome  at  any  time,  became  intolerable.  When  the 
time  came  for  evacuating  the  stomach  contents,  all  that 
the  subject  had  to  do  when  the  basin  was  in  place,  was 
simply  to  turn  on  the  side,  and  with  one  sudden  act  of 
vomiting,  everything  left  the  stomach.  Water  was  subse- 
quently taken,  in  order  to  clean  out  the  stomach  as  much 
as  possible.  This  was  also  immediately  rejected,  bringing 
with  it  nothing  but  mucus.  The  amount  of  chyme  re- 
covered was  3xi.  It  was  now  10.18  a.m.  The  boat  had 
been  out  since  8.53  a.m.,  and  was  not  expected  to  return 
before  6  or  7  p.m.  On  this  account  it  was  decided  not 
to  try  the  effect  of  drugs  until  the  afternoon.  Subject 
"B"  felt  much  relieved  for  having  his  stomach  emptied 
and  irrigated.  After  a  time,  however,  his  wretchedness 
returned,  and  he  was  obliged  t»  take  to  the  floor  again  and 
wedge  himself  in  an  angle  as  best  he  could  to  keep  from 
being  tossed  about.  By  this  time  he  was  very  irritable, 
and  the  swirl  of  the  water  rushing  past  the  side  of  the  boat 
was  extremely  annoying.  However,  there  was  nothing  left 
for  him  but  passive  resistance,  which,  in  the  sick  and 
helpless,  often  represents  the  very  acme  of  courage.  He 
had  made  up  his  mind  that  the  struggle  was  to  be  a  long 
one,  and  bowed  to  the  inevitable.  At  12  m.,  however, 
it  was  an  agreeable  surprise  to  find  that  the  boat  was 
"  alongside  the  wharf"  and  everything  ready  to  go  ashore. 
On  inquiry  it  was  learned  from  the  skipper,  that  owing 
to  the  rough  weather,  the  fishing  nets  had  been  swept 
away,  and  it  was  considered  too  risky  to  remain  out 
longer. 

The  condition  of  the  circulation  was  studied  with  great 
difficulty  on  this  trip,  and  only  at  irregular  intervals. 
The  results  are  shown  in  protocol  18.  There  was  a  good 
deal  of  muscular  activity  at  all  times  when  the  blood- 
pressure  was  taken.  When  the  subject  was  lying  quietly, 
if  that  were  possible  at  any  time,  there  were  manifest 
signs  of  profound  circulatory  depression.  In  the  after- 
noon subject  "B"  felt  exceedingly  nervous  and  irritable. 
It  was  only  after  several  hours  in  bed  that  the  effects  of 
his  rough  tilt  with  the  sea  wore  off.     He  had  a   slight 


870  SEASICKNESS 

headache,  and  every  fibre  in  his  limbs  and  body  was  in  a 
tremour.  Even  a  two  hours'  sleep  did  not  relieve  his  ner- 
vousness. The  "lump-sensation"  in  the  stomach,  which 
made  its  appearance  upon  the  boat,  remained  with  him 
as  late  as  5  p.m.  The  blood-pressure  was  well  maintained, 
however,  but  the  vaso-motor  system  was  evidently  still 
demoralized.  Analysis  after  the  test  meal  showed  absence 
of  HCl,  both  free  and  combined,  and  a  total  acidity  of 
.021%  by  wt.  Tests  were  made  for  the  presence  of  the 
gastric  enzymes,  but  an  unfortunate  accident  destroyed 
the  specimens  before  the  customary  time  had  elapsed.  It 
was  ascertained,  however,  that  in  the  case  of  chymosin 
(rennet)  coagulation  was  retarded  considerably.  It  may, 
therefore,  be  assumed  that  the  ferments  were  diminished. 
Both  the  K  I  and  salol  tests  were  negative,  not  only  dur- 
ing the  trip,  but  all  through  the  afternoon.  It  was  evi- 
dent that  no  absorption  had  taken  place,  and  that  nothing 
had  escaped  into  the  intestines. 

Analysis  after  the  test  meal  given  subject  "S"  and  re- 
tained 26  minutes,  showed  total  acidity  .048%  by  wt., 
with  HCl  both  free  and  combined  absent.  The  K  I  and 
salol  tests  were  negative  during  the  trip  and  all  through 
the  afternoon. 

The  first  urine  passed  by  subject  "B"  after  leaving 
the  boat,  was  in  amount  3V,  and  slightly  turbid,  due  to 
the  presence  of  an  excessive  amount  of  mucus.  The  spe- 
cific gravity  was  1.028.  There  was  no  evidence  of  albu- 
min or  of  sugar.     Glycuronic  acid  was  present. 


Analysis  of  specimen  taken  July  22d  on  the  Quatre  Freres,  from 
subject  "B."  Ing-ested  at  9.10  a.m.  an  Ewald  breakfast. 
Withdrawn  (vomited)  at  10.10  a.m.  Amount  of  chyme, 
|xi.  Reaction  faintly  acid  (litmus).  Free  HCl  (resorcin), 
absent. 

Tot.   acidity,    6,  or  .021%  by      Erythrodextrin,  present, 

wt,  Achroodextrin,  present. 

Free  HCl,  absent.  Maltose,  present. 

Comb'd  HCl,  absent.  Coagnlating  enzymes,    dimin- 

Tot.  HCl,  .  ished. 

Acid  salts,  .  Peptones,  faint  trace. 

Lactic  acid  (direct),  trace.  Bile,  absent. 

Starch,  absent.  Mucus,  abundant. 

Amylodextrin,  trace.  Blood,  absent. 


SEASICKNESS  371 

Analysis  of  specimen  taken  July  22d  on  the  Quatre  Freres,  from 
subject  "S. "  Ingested  at  9.10  a.m.  an  Ewald  breakfast. 
Withdrawn  (vomited)  at  9.36  a.m.  Amount  of  chyme,  ^viii. 
Reaction  faintly  acid  (litmus).    Free  HCl  absent  (resorcin). 

Tot.  acidity,    12,  or  .043%  by      Amylodextrin,  present. 

wt.  Erythrodextrin,  present. 

Free  HCl,  absent.  Achroodextrin,  present. 

Comb'd  HCl,  absent.  Maltose,  present. 

Tot.  HCl,  .  Peptones,  trace. 

Acid  salts,  .  Bile,  absent. 

Lactic  acid  (direct),  trace.  Mucus,    considerable  amount. 

Starch,  absent.  Blood,  absent. 

Jiily  23d.. — At  Cherbourg  the  steamship  Sotdhtvestern, 
bound  for  Southampton,  was  boarded  at  10.12  p.m.  At 
11.47  p.m.  subjects  "B"  and  "S"  received  each,  hypo- 
dermatically,  gr  1/75  of  atropin  sulphate,  and  gr  1/40  of 
strychnin  nitrate. 

Jaly  24th. — At  12.05  a.m.  the  boat  started,  and  at 
12.34  a.m.  an  Ewald  test-meal  w^as  given  to  each  subject. 
The  weather  was  very  rough.  The  boat  pitched,  twisted, 
and  rolled  badly.  On  this  occasion  the  party  travelled  in 
the  second  cabin,  as  the  sleeping  compartment  was  situated 
in  the  bow  where  the  motion  was  certain  to  be  at  its  worst, 
and  where  one  would  be  most  liable  to  be  made  seasick. 
The  berths  were  ranged  around  the  sides  of  the  ship  as  in 
a  dormitory.  The  boat  had  scarcely  started,  when  the 
passengers  began  to  climb  into  their  beds,  and  in  a  very 
few  minutes  no  one  was  astir  but  the  members  of  our 
party.  Here  an  amusing  incident  occurred  which  those 
who  practise  psychic  therapeutics  will  appreciate.  The 
boat  had  been  behaving  badly,  and  there  was  every  indi- 
cation that  there  were  rough  times  ahead.  Suddenly  the 
steward,  a  good-natured  fellow,  appeared  with  an  armful 
of  large  white  basins  made  of  agate  or  papier  mache. 
One  of  these  was  placed  beside  the  head,  you  might  say 
under  the  nose  of  each  passenger  in  a  smart,  businesslike 
way,  as  much  as  to  say,  "There!  now  it's  up  to  you." 
The  steward  made  the  round  of  the  compartment  in  quick 
time,  but  he  had  scarcely  placed  the  last  basin,  when  almost 
every  one  in  the  place  commenced  vomiting.  He  even  had 
the  temerity  to  place  basins  in  front  of  subjects  "B"  and 
"S"  and  as  he  did  so,  he  leered  at  them  out  of  the  corner 
of  his  eye,  tg  ^ee  how  they  were  standing  the  pace.     It  was 


872  SEASICKNESS 

easily  understood  why,  for  sanitary  and  economic  reasons, 
vessels  should  be  placed  convenient  to  the  passengers,  but 
it  was  not  at  the  time  so  apparent  why  the  steward  should 
so  jauntily  rattle  his  basins  as  he  placed  them  around. 
His  conduct  seemed  more  intelligible  the  next  morning 
when  it  was  learned  from  stickers  placed  conspicuously  in 
various  parts  of  the  boat  that  a  certain  remedy  was  a  sure 
cure  for  seasickness  and  that  it  could  be  had  at  any  time 
from  the  steward,  price  two  shillings  and  nine  pence.  The 
test  meals  were  eaten  with  relish,  and  although  the  boat 
pitched  and  rolled  very  badly,  no  ill  effects  were  felt.  In  the 
stomach  there  was  a  cool,  agreeable  sensation,  as  though 
one  had  just  eaten  ice-cream.  No  perversion  of  the  sense 
of  smell  was  experienced.  There  was  a  peculiar  sour  taste 
in  the  mouth  as  though  one  were  eating  unripe  apples. 
The  saliva  was  not  free,  and  yet  the  mouth  was  not  dry. 
Both  subjects  felt  an  inclination  for  work.  The  balancing 
movements  necessitated  by  the  rolling  of  the  ship  were 
effectually  and  easily  executed,  without  the  usual  anxiety 
and  awkwardness.  The  subjects  sat,  stood,  and  walked 
about  at  various  times  during  the  hour  that  the  test  meals 
were  retained.  They  felt  exceedingly  well  during  all  the 
tossing  and  tumbling  of  the  boat.  At  times  subject  "B," 
who  is  extremely  susceptible  to  seasickness,  felt  a  slight 
transitory  fulness  in  the  head.  There  were  no  symptoms 
referable  to  the  stomach,  in  fact  an  agreeable  feeling  was 
associated  with  that  organ.  There  was  no  psychic  depres- 
sion or  distress.  At  1.07  a.m.,  subject  "B"  still  felt  well, 
but  on  standing  up  was  almost  thrown  by  the  rolling  of  the 
boat.  Although  feeling  well  he  was  disinclined  to  stand 
up  or  walk  about.  At  this  time  there  was  a  slight  inti- 
mation of  the  "lump-sensation"  in  the  stomach,  though 
no  disagreeable  feeling  was  associated  with  it. 

When  the  boat  gave  an  unusually  heavy  lurch,  lioth 
subjects  felt  it  affect  their  heads  momfsntarily,  but  no 
worry  or  distress  was  induced.  At  1.83  a.m.,  subject 
^^R"  experienced  a  pronounced  "lump-sensation"  with  a 
slight  sense  of  nervousness  or  tremour  in  the  muscles. 
Subject  "S"  felt  no  lump-sensation  in  the  stomach  at  any 
time. 

At  1.50  a.m.,  the  stomach  contents  of  subject  "B" 
were  removed.     The  amount  of  chyme  obtained  we^s  ^iy, 


SEASICKNESS  373 

A  little  blood  also  came  with  the  chyme.  Analysis  showed : 
total  acidity,  .075%  by  wt. ;  combined  HCl,  .051,  and 
free  HCl  absent. 

The  tests  for  enzymes  showed  diminution  or  absence 
of  these  bodies. 

The  K  I  absorption  test  showed  the  presence  of  iodin 
in  the  saliva  in  11  minutes.     The  salol  test  was  negative 
A  faint  reaction  occurred  in  50  minutes,  but  was  of  too 
doubtful  a  nature  to  afford  basis  for  a  conclusion  as  to 
stomach  motility. 

Analysis  of  specimen  taken  at  1.50  a.m.,  July  24th,  on  the 
steamship  Southwestern  from  subject  "B"  after  hypoder- 
mic injection  of  strychnin  nitrate,  gr  140,  and  atropin 
sulphate,  gr  175.  Ingested  at  12.34  a.m.  an  Ewald  test  meal. 
Withdrawn  at  1.50  a.m.  Amount  of  chyme,  siv.  Reaction 
to  litmus,  acid.     Free  HCl  absent  (resorcin). 

Tot.  acidity,   20,  or  .073%  by  Erythrodextrin,  present. 

wt.  Achroodextrin,  present. 

Free  HCl.  absent.  Maltose,  present. 

Comb'd  HCl,    14,  or  .051%  by  Peptones,  trace. 

wt.  Bile,  absent. 

Tot.  HCl,  14,  or  .051%  by  wt.  Mucus,  moderate  amount. 

Acid  salts,  .  Blood,  trace. 

Chymosin,  deficient. 

Lactic  acid  (direct),  trace.  Peptonizing  enzymes,  absent. 

Starch,  absent.  Peptonizing  zymogens,  defi- 
Amylodextrin,  trace.  cient. 

At  2  a.m.,  the  stomach  contents  were  withdrawn 
from  subject  "S."  The  amount  of  chyme  was  |iv. 
Analysis  showed:  total  acidity,  .21%  by  wt. ;  free  HCl, 
.11;  combined  HCl,  .08.  The  K  I  absorption  test  showed 
the  presence  of  iodin  in  the  saliva  in  16  minutes.  The 
salol  test  was  negative  at  all  times. 

Analysis  of  specimen  taken  at  2  a.m.,  July  24th,  from  subject 
"S,"  on  the  steamship  Southivestern,  after  hypodermic  in- 
jection of  strychnin  nitrate,  gr  1  40,  and  atropin  sulphate, 
gr  1  75.  Ingested  at  12.34  a.m.  an  Ewald  test  meal.  With- 
drawn at  2  a.m.  Amount  of  chyme,  siv.  Resorcin  test 
showed  the  presence  of  free  HCl. 

Tot.  acidity,    58,  or  .211%  by  Tot.  HCl,  56,  or  .19%  by  wt. 

wt.  Acid  salts,  2,  or  .007%  by  wt, 
Free  HCl,    32,  or  .11%  by  wt. 

Comb'd  HCl,    24,  or  .08%  by  Lactic  acid  (direct),  trace. 

wt.  Starch,  absent. 


874  SEASICKNESS 

Amylodextrin,  absent.  Coagulating  enzymes,  normal. 

Erythrodextrin,  present.  Peptonizing  enzymes,  normal. 

Achroodextrin,  present.  Bile,  absent. 

Maltose,  present.  Mucus,  moderate  amount. 

Peptones,  present.  Blood,  absent. 

The  circulation  was  well  maintained,  as  shown  in  pro- 
tocol 19.  The  vaso-motor  apparatus  was  evidently  in  a 
keen,  steady  state  of  activity  and  did  its  part  in  main- 
taining the  blood-pressure  without  increase  of  the  pulse- 
rate.  Muscular  activity  was  in  part  responsible  for  the 
high  blood-pressure. 

From  the  foregoing  experience  there  can  be  no  question 
of  the  beneficial  effects  of  strychnin  combined  with 
atropin.  The  conditions  of  this  journey  were  such  that 
without  these  drugs  both  subjects  would  have  been  very 
seasick.  Each  subject  after  irrigation  of  the  stomach  went 
to  bed  and  slept  well.  Both  had  a  free  action  of  the  bowels 
on  arising,  and  both  felt  well  in  every  way. 

July  24th. — At  11.22  p.m.,  the  steamship  Southioest- 
em  was  boarded  at  Southampton,  bound  for  Cherbourg. 
At  11.23  p.m.,  subject  "S"  received  gr  Ix  of  potassium 
bromid,  and  at  11.50  subject  "B"  received,  hypodermic- 
ally,  atropin  sulphate,  gr  1/80. 

July  25th.— At  12.08  a.m. ,  the  boat  started.  At  12.36 
subject  "B"  was  given  an  Ewald  test-meal.  At  12.40 
subject  "S"  was  given  a  similar  meal.  The  weather  was 
not  rough  during  this  i3art  of  the  night,  but  the  boat  rolled 
and  pitched  considerably.  Both  subjects  experienced  the 
"lump-sensation"  in  the  stomach  for  a  time.  Neither 
subject  at  any  time  experienced  more  than  a  passing 
"feeling  in  the  head,"  i.e.,  dizziness  when  the  boat  gave 
an  unusual  lurch.  In  subject  "B"  the  sense  of  smell  was 
slightly  perverted,  tobacco-smoke  smelling  like  burnt 
rags. 

The  test  was  a  fair  one  in  so  far  as  subject  "B"  w^s 
concerned,  for  owing  to  his  sensitiveness  to  seasickness, 
the  trip  would  undoubtedly  have  sufficed  to  sicken  him 
thoroughly.  Subject "  S, "  however,  is  less  susceptible,  and 
would  probably  have  been  fairly  well  through  such  weather 
as  was  encountered.  In  subject  "B"  the  atropin  again 
caused  a  peculiar  sour  taste  in  the  mouth.     At  1.40  a.m., 


SEASICKNESS  875 

the  test  meal  was  withdrawn  from  subject  '*B's"  stomach. 
The  amount  of  chyme  obtained  was  3iiss.  When  its  con- 
tents had  been  evacuated,  the  stomach  was  irrigated  and 
a  good  deal  of  mucus  with  a  little  blood  was  removed. 
Analysis  showed:  total  acidity,  .073%  by  wt. ;  free  HCl, 
absent;  combined  HCl,  .058.  The  K  I  absorption  test 
showed  a  positive  reaction  in  14  minutes.  The  salol  test 
did  not  react  at  any  time. 

Analysis  of  specimen  taken  July  25th,  on  steamship  South- 
western from  subject  "B,"  after  atropin  sulphate,  gr  1/80 
hypodermically.  Ingested  at  12.36  a.m.  an  Ewald  test- 
meal.  Withdrawn  at  1.40  a.m.  Amount  of  chyme,  |iiss. 
Reaction  (litmus),  acid.     Free  HCl  absent  (resorcin). 

Tot.  acidity,    20,  or  .073%  by  Starch,  absent. 

wt.  Amylodextrin,  absent. 

Free  HCl,  absent.  Erythrodextrin,  present. 

Comb'd  HCl,    16,  or  .058%  by  Achroodextrin,  present. 

wt.  Maltose,  present. 

Tot.  HCl,  16,  or  .058%  by  wt.  Bile,  absent. 

Acid  salts    .  Mucus,  considerable  amount. 

Blood,  trace. 

Lactic  acid  (direct),  trace.  Enzymes,  diminished. 

At  1.50  a.m.,  the  contents  of  subject  "S's"  stomach 
were  withdrawn.  The  amount  of  chyme  recovered  was 
|v.  Analysis  showed:  total  acidity,  .277%  by  wt. ;  free 
HCl,  .189;  combined  HCl,  .08.  The  K  I  absorption  test 
showed  a  positive  raection  in  10  minutes.  The  salol  test 
showed  no  reaction  at  any  time.  After  evacuation  of  its 
contents,  the  stomach  was  irrigated. 

Analysis  of  specimen  taken  July  25th  on  steamship  South- 
western from  subject  "S"  after  KBr.  gr  Ix.  Ingested 
at  12.40  a.m.  an  Ewald  meal.  Withdrawn  at  1.50  a.m. 
Amount  of  chyme,  sv.  Resorcin  test  showed  the  presence 
of  free  HCl. 

Tot.  acidity,    76,  or  .277%  by  Amylodextrin,  trace. 

wt.  Erythrodextrin,  present. 

Free  HCl,  52,  or  .189%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,  22,  or  .080%,  by  Maltose,  present. 

wt.  Peptones,  present. 

Tot.  HCl,  74,  or  .269%  by  wt.  Bile,  absent. 

Acid  salts,  2,  or  .007%  by  wt.  Mucus,  moderate  amount. 

Lactic  acid  (direct),  absent.  Blood,  absent. 

Starch,  absent,  Enzymes,  normal. 


376  SEASICKNESS 

Whilst  the  test-meals  were  in  the  stomach,  subject 
*'B"  felt  somewhat  drowsy,  but  subject  "S"  was  wakeful. 
When  the  work  with  the  test  meals  was  finished,  the 
weather  became  rather  rough,  but  both  subjects  went  to 
bed  and  slept  soundly  without  suffering  any  ill  effects. 
Cherbourg  was  reached  about  7  a.m. 

There  can  be  little  question  that  on  this  occasion  atro- 
pin  served  subject  "B"  well  in  warding  off  the  disagree- 
able effects  which  would  certainly  have  been  experienced 
without  its  use.  It  is  to  be  noted  here,  as  in  rotations 
and  aural  irrigations,  that  atropin  is  of  no  benefit  what- 
ever in  tending  to  relax  the  pylorus  in  the  presence  of  irri- 
tation of  the  medullary  centres.  The  bromid  of  potassium 
had  an  effect  similar  to  that  exhibited  by  it  in  rotations. 
It  lessened  psychic  distress,  and  the  fear  of  what  was  to 
come.  On  this  occasion,  however,  it  must  be  said  that 
the  conditions  were  not  quite  such  as  would  properly  test 
the  efficiency  of  the  drug. 

July  26th. — At  9.50 p.m. ,  the  steamship  SoutMcester^i, 
bound  for  Southampton  from  Cherbourg,  was  boarded.  At 
9.55  p.m.,  subject  "B"  was  given, ^er  05,  gr  Ix  of  potas- 
sium bromid.  At  10.89  subject  "S"  received  atropin 
sulphate,  gr  1/50,  2^er  os. 

July  27th. — At  12.06 a.m.,  each  subject  was  given  an 
Ewald  meal. 

At  12.17  subject  "B"  was  given  orthoform,  gr  v. 

On  this  occasion  the  weather  was  fairly  rough.  The 
boat  pitched  and  rolled  considerably.  Subject  "B"  ex- 
perienced all  the  symptoms  of  the  severe  form  of  seasick- 
ness. The  "lump-sensation"  was  present  in  the  stom- 
ach and  throat.  There  were  also  present  nausea,  increased 
salivary  flow,  pain  in  the  left  region  of  the  epigastrium, 
nervousness  and  irritability  of  temper;  general  muscular 
weakness  with  tremulousness;  a  full,  sickening  feeling 
about  the  ears ;  occipital  headache,  worse  toward  the  right 
side,  a  sense  of  fulness  and  liglitness  in  the  head,  especi- 
ally in  the  mastoid  regions  and  behind  the  eyeballs.  At 
times  there  was  pain  in  the  right  as  well  as  in  the  left 
f^pigastric  region.  The  subject  also  felt  chilly  and  drowsy. 
The  face  was  flushed,  the  pupils  normal,  the  conjunctivae 
congested,  and  the  skin  cold.     He  was  very  anxious  to  lie 


SEASICKNESS  877 

down,  which  indeed  he  had  to  do  in  order  to  retain  the 
test  meal  for  the  customary  hour.  At  1.07  a.m. ,  the  stom- 
ach contents  of  subject '  •  B "  were  withdrawn.  The  amount 
of  ch}Tne  recovered  was  $vi.  Analysis  showed:  total  acid- 
ity, .080  by  wt. ;  free  HCl,  absent,  and  combined  HCl,  .058. 
The  K  I  absorption  test  showed  a  positive  reaction  in  19 
minutes.  The  salol  test  did  not  react  at  any  time,  the 
stomach  having  been  irrigated  after  its  contents  had  been 
withdrawn.  The  irrigation  of  the  stomach  gave  the  sub- 
ject great  relief  from  his  S}Tnptoms,  nevertheless  each  roll 
of  the  ship  caused  that  indescribable  sickening  feeling 
which  elsewhere  has  been  called  dolor  cerebri.  The  sub- 
ject was  very  glad  to  get  back  to  bed. 

Analysis  of  specimen  taken  July  27th  on  the  steamship  South- 
western, from  subject  "B"  after  receiving,  per  os,  K  Br., 
gr  Ix,  and  orthoform,  gv  v.  Ingested  at  12.06  a.m.  an  Ewald 
meal.  Withdrawn  at  1.97  a.m.  Amount  of  chyme,  §vi. 
Reaction  (litmus),  acid.    Free  HCl,  absent  (resorcin). 

Tot.  acidity,    22,  or  .080%  by  Amylodextrin,  absent. 

wt.  Erythrodextrin,  present. 

Free  HCl,  absent.  Achroodextrin,  present. 

Comb'd  HCl,    16,  or  .058%  by  Maltose,  present. 

wt.  Peptones,  trace. 

Tot.  HCl,  16,  or  .058%  by  wt.  Bile,  absent. 

Acid  salts,  .  Mucus,  moderate  amount. 

Lactic  acid  (direct),  trace.  Blood,  absent. 

Starch,  absent.  Enzymes,  deficient  or  absent. 

With  the  exception  of  a  sense  of  fulness  in  the  head, 
and  a  slight  pain  in  the  right,  and  also  at  times  in  the 
left  epigastric  region,  subject  "S"  felt  fairly  comfortable. 

At  1.20  a.m.  his  stomach  contents  were  withdrawn. 
The  amount  of  chyme  recovered  was  3xii.  The  stomach 
was  irrigated,  and  the  symptoms  previously  mentioned 
disappeared,  i.e.,  the  pain  in  the  epigastrium  and  the 
sensation  of  fulness  in  the  head. 

Analysis  showed:  total  acidity,  .255%bywt. ;  free 
HCl,  .183;  combined  HCl,  .109. 

The  K  I  absorption  test  showed  a  positive  reaction  in 
24  minutes.  The  salol  test  did  not  react  at  any  time,  the 
stomach  having  been  irrigated  after  its  contents  had  been 
removed.  The  subject  stood  up  all  through  the  period 
during  which  the  test  meal  was  retained. 


378  SEASICKNESS 

Analysis  of  specimen  taken  July  27th  on  steamship  Southwest- 
ern, from  subject  "S,"  after  atropin,  gr  1/50,  per  os.  In- 
gested at  12.06  a.m.  an  Ewald  test  meal.  Withdrawn  at 
1.20  a.m.    Amount  of  chyme,  Ixii. 

Tot.  acidity,    70,  or  .255%  by  Amylodextrin,  trace. 

wt.  Erythrodextrin,  present. 

Free  HCl,  34,  or.  133%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,    30,  or  .109%  by  Maltose,  present. 

wt.  Peptones,  present. 

Tot.  HCl,  64,  or  .242%  by  wt.  Bile,  absent. 

Acid  salts,  6,  or  .021%  by  wt.  Mucus,  moderate  amount. 

Lactic  acid  (direct),  absent.  Blood,  absent. 

Starch,  absent.  Enzymes,  normal. 

The  experiences  of  this  trip  show  that  neither  bromid 
of  potassium  nor  orthoform  has  any  potent  action  in 
counteracting  the  effects  of  seasickness.  They  also  show 
that  atropin  jjer  os  may  be  used  in  seasickness  to  advan- 
tage, but  not  with  such  good  effect  as  when  used  hypoder- 
matically  and  in  combination  with  strychnin.  It  was 
observed  that  the  effect  upon  the  bowels  was  not  so  happy 
after  bromid  as  after  atropin  and  strychnin. 

The  subject  experienced  a  sour  taste  after  the  bromid, 
similar  to  that  experienced  with  atropin. 

July  27th. — A  trip  was  made  on  the  steamship  Lorna 
Doone  from  Southampton  to  Southsea.  The  boat  started 
at  9.15  a.m.     The  morning  was  fine  and  the  water  calm. 

No  ill  effects  were  experienced,  but  on  the  return  trip  in 
the  evening  the  weather  was  wet  and  dismal,  and  the  boat 
rolled  and  pitched  somewhat.  Subject  "B"  felt  many  of 
the  milder  symptoms  of  seasickness,  but  the  journey  was 
too  short  to  cause  much  trouble  under  the  conditions  pre- 
vailing. 


CHAPTER  XXVII 

STUDIES    IN   SEASICKNESS    (Continued) 

July  28th. — After  a  good  night's  rest  in  a  cool  room 
on  shore  at  7.18  a.m.  each  subject  was  given  an  Ewald 
test  breakfast.  At  8.25  the  stomach  contents  of  subject 
"B"  were  withdrawn.  The  amount  of  chyme  recovered 
was  5ii-  It  was  mixed  with  much  mucus.  Free  HCl 
was  absent.  Unfortunately  the  specimen  was  thrown  away 
by  accident  before  the  quantitative  examination  was  made. 
The  K  I  test  showed  a  positive  reaction  in  21  minutes. 
The  salol  test  did  not  react  at  any  time,  the  stomach  hav- 
ing been  irrigated  when  its  contents  had  been  removed. 

At  8.80  the  stomach  contents  of  subject  "S"  were  re- 
moved. The  amount  of  chyme  recovered  was  |ss.  This 
specimen  was  also  thrown  away  by  mistake,  but  not  until 
it  had  been  ascertained  that  it  contained  free  HCl.  The 
amount  of  mucus  was  very  moderate.  The  K  I  test  showed 
a  positive  reaction  in  16  minutes.  The  salol  test  reacted 
strongly  in  1  hour  12  minutes.  The  condition  of  sub- 
ject "B's"  circulation  after  a  restful  night  in  a  cool  room 
is  shown  in  protocol  19.  The  cardiac  and  neuro-vascular 
mechanisms  were  in  good  working  order.  The  subject 
felt  well  in  every  way,  except  for  an  occasional  feeling  of 
indigestion. 

At  11.52  a.m.,  the  steamship  Teutonic,  bound  for  New 
York  from  Southampton,  was  boarded.  As  shown  in  pro- 
tocol 20,  the  subject's  circulation,  before  the  boat  started, 
manifested  some  depression  incidental  to  the  fatigue  of 
making  preparations  to  go  on  board.  At  12.15  p.m.  the 
boat  started.  The  weather  was  mild  and  clear.  The  boat 
was  very  steady,  but  some  slight  vibration  was  felt  from 
the  machinery.  Subject  "B"  felt  well  in  every  way.  He 
took  his  meals  and  enjoyed  them.  After  the  evening  meal, 
however,  he  had  a  slight  feeling  of  indigestion.  The  cir- 
culation as  shown  in  protocol  20  was  efficiently  maintained. 

379 


880  SEASICKNESS 

July  29th. — After  lying  all  the  morning  in  ^ueenstowH 
Harbour,  the  pilot  was  put  off  at  1.15  p.m.,  and  the  boat 
got  away  under  full  steam.  During  the  afternoon  the  boat 
pitched  somewhat.  This,  with  the  jolting  of  the  machinery, 
caused  subject  "  B"  to  have  occipital  headache,  worse  upon 
the  right  side,  with  an  occasional  sick  feeling  in  the  head, 
as  the  ship  made  an  unusually  bad  lurch.  Toward  9 
o'clock  the  ship  was  pitching  considerably  and  subject 
"B"  had  the  "lump-sensation"  in  the  stomach  to  a 
marked  degree.  This  was  temporarily  relieved  by  10 
drops  of  dilute  HCl,  in  water,  but  it  returned  later  and 
was  as  bad  as  ever.  The  effects  of  the  pitching  of  the 
ship  began  to  tell  upon  the  circulation  as  seen  in  protocol 
21.  The  vaso-motor  tone  was  not  as  efficient  in  the  late 
afternoon  and  evening  as  it  had  been  earlier  in  the  day. 

July  30th. — At  7.40  a.m.  both  subjects  felt  very  well 
after  a  good  night.  Each  was  given  an  Ewald  breakfast. 
At  8.47  the  stomach  contents  of  subject  "B"  were  evacu- 
ated. The  amount  of  chyme  recovered  was  |iii.  Analysis 
showed  absence  of  free  HCl.  Quantitative  determinations 
were  not  made,  owing  to  an  accident.  A  considerable 
amount  of  mucus  was  present.  The  K  I  absorption  test 
showed  a  positive  reaction  in  31  minutes.  The  salol  test 
reacted  in  55  minutes.  At  8.59  the  stomach  contents  of 
subject  "S"  were  removed.  The  amount  of  chyme  recov- 
ered was  5  iii-  Analysis  showed:  total  acidity,  .262% 
by  wt.,  free  HCl,  .175,  combined  HCl,  .080.  The  KI 
test  showed  a  positive  reaction  in  32  minutes.  The  salol 
test  did  not  react  at  any  time,  the  stomach  having  been 
irrigated  after  its  contents  had  been  removed. 

Analysis  of  specimen  taken  July  30th  on  the  steamship  Teutonic, 
from  subject  "S. "  Ingested  at  7.40  a.m.  an  Ewald  break- 
fast. Removed  at  8.59.  Amount  of  chyme,  §iii.  Resorcin 
test  showed  the  presence  of  free  HCl. 

Tot.   acidity,    72,  or  .262%  by  Amylodextrin,  trace. 

wt.  Erythodextrin,  present. 

Free  HCl,  48,  or  .175%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,    22,  or  .080%  by  Maltose,  present. 

wt.  Peptones,  present. 

Tot.  HCl,  70,  or  .255%  by  wt.  Bile,  absent. 

Acid  salts,  2,  or  .007%  by  wt.  Mucus,  moderate  amount. 

Lactic  acid  (direct),  absent.  Blood,  absent. 

Starch,  absent.  Enzymes,  normal. 


SEASICKNESS  881 

In  the  afternoon  the  sea  became  very  rough  and  many 
people  were  made  seasick.  Subject  "B"  experienced  no 
disagreeable  symptoms  except  a  ' '  slight  lump-sensation' ' 
in  the  stomach.  At  5. 11  p.m.  the  stomach-tube  was  in- 
troduced and  siss.  of  chyme  removed.  This  was  the  re- 
mains of  a  meal  taken  at  1.10  p.m.,  and  consisting  of 
pea-soup,  boiled  codfish,  mashed  potatoes,  boiled  rice  and 
water,  3viii.  Analysis  showed  free  HCl,  .073%.  This 
subject  "B"  felt  exceedingly  well  in  spite  of  the  very 
rough  weather.  Whatever  slight  trouble  he  experienced 
should  be  attributed,  perhaps,  to  his  indigestion.  The 
condition  of  the  circulation  as  represented  in  protocol  22 
;shows  the  vaso-motor  mechanism  to  be  thoroughly  effective 
toward  the  latter  part  of  the  day. 

July  81st. — On  this  day  the  weather  was  fair  and  the 
boat  steady.  After  breakfast  at  9.05  a.m.  the  K  I  absorp- 
tion test  showed  a  positive  reaction  in  1  hour  and  5  min- 
utes in  subject  "B. "  The  salol  motility  test  reacted  in 
2  hours  and  22  minutes.  This  subject  "B"  felt  very  well 
all  day.  At  times  during  the  day  he  had  slight  intima- 
tions of  indigestion.  The  condition  of  the  circulation  is 
shown  in  protocol  28.  The  blood-pressure  was  well  main- 
tained in  the  normal  manner,  excepting  at  times  when  the 
effects  of  the  hot  stuffy  cabin  manifested  themselves  by 
impaired  vaso-motor  tonus. 

August  1st. — On  this  day  the  weather  was  warm,  but 
on  account  of  rain  and  mist  the  port-holes  were  kept  closed. 
Subject  "  B"  felt  well  in  every  way  except  for  an  occasional 
feeling  of  indigestion.  He  had  no  symptoms  that  could 
be  attributed  to  the  motion  of  the  boat.  The  circulation 
as  sho-sATi  in  protocol  24  was  not  properly  maintained  in 
the  normal  manner.  There  is  evidence  of  vaso-motor  in- 
efficiency which  is  perhaps  to  be  attributed  to  the  effects 
of  the  warm  stuffy  cabin.  The  effects  of  hot  and  cold  air 
upon  the  circulation  are  of  importance  not  only  in  seasick- 
ness, but  in  any  condition  where  the  vaso-motor  tone  needs 
watching.  As  we  have  seen,  time  and  again,  seasickness 
is  not  due  primarily  to  disturbance  of  the  circulation  and 
yet  the  latter  is  such  a  usual  and  constant  phenomenon  in 
the  malady  that  whatever  hinders  or  helps  the  efficiency 
of  the  circulatory  mechanisms  becomes  a  matter  of  mo- 
ment to  the  sufferer.     The  good  effect  of  cool  fresh  air 


382  SEASICKNESS 

upon  the  circulation  is  well  shown  in  protocol  24,  at  4. 04 
p.m.,  where  there  is  every  indication  of  keen  vaso-motor 
efficiency.  The  difference  between  the  torpid  neuro-vas- 
cular  mechanism  and  the  neuro-vascular  mechanism  that 
is  exhausted  from  overstimulation  should  constantly  be 
remembered.  In  the  former  condition  the  mechanism  is 
intact  and  measures  to  rouse  it  to  activity  may  be  em- 
ployed, such  as  mild  exercise,  friction,  thermic  stimulation 
by  cold  bathing,  and  even  drugs.  In  the  latter  condition, 
which  is  the  characteristic  one  of  true  seasickness,  the 
neuro-vascular  mechanism  is  exhausted  from  overwork. 
For  all  practical  purposes  of  therapy  intended  to  directly 
enhance  vaso-motor  efficiency,  there  is  no  neuro-vascular 
mechanism,  and  it  is  irrational  and  harmful  to  try  to 
stimulate  the  medullary  centres  or  the  sympathetic  nervous 
system  under  these  conditions.  Here  the  problem  has  to 
be  approached  from  the  other  side.  If  nothing  may  be 
done  directly  to  enhance  lessened  vaso-motor  efficiency  the 
most  should  be  made  of  what  remains  by  conserving  the 
circulatory  mechanisms  and  diminishing  to  the  utmost 
the  demands  put  upon  them.  The  principle  of  adaptation 
of  the  functional  activities  to  the  capacity  of  any  organ  or 
set  of  organs,  or  to  the  capacity  of  the  organism  as  a 
whole,  finds  application  in  seasickness  as  in  every  other 
condition  that  faces  the  medical  strategist.  Any  kind 
of  treatment  that  offers  hope  must  not  be  employed.  A 
thorough  understanding  of  the  underlying  causes  and  con- 
ditions is  imperative  in  order  that  the  best  method  of 
treatment  in  the  individual  case  may  be  discovered  and 
applied. 

August  2d. — The  effects  of  a  hot,  stuffy  cabin  upon 
the  circulation  are  shown  in  parts  of  protocols  24  and  25. 
The  contrast  between  the  condition  of  the  circulation  after 
a  night  in  a  close  cabin  and  when  the  port-holes  were  open 
later  in  the  morning,  challenges  attention.  See  protocol 
25.  The  vaso-motor  efficiency  from  11.86  a.m.  until 
9.53  p.m.  was  perfect.  During  all  this  time  the  port- 
holes were  open,  the  temperature  of  the  cabin  being  about 
68°  F. 

After  breakfast  at  9.36  a.m.  the  K  I  absorption  test 
showed  in  subject  "B"  a  positive  reaction  in  27  minutes. 
At  9.55  a.m.  subject  "B"  took  ten  drops  of  dilute  HCl, 


SEASICKNESS  383 

to  ascertain  whether  it  would  hasten  the  progress  of  food 
through  the  pylorus.  It  was  noted  that  the  salol  test 
showed  a  positive  reaction  in  exactly  the  same  time  that 
it  took  upon  July  31st,  viz.,  2  hours  and  23  minutes. 
Observations  on  subject  "S"  showed  that  the  cool  cabin 
had  little  effect  in  restoring  vaso-motor  efficiency.  This 
subject's  vaso-motor  mechanism,  as  we  have  before  re- 
marked, is  of  an  altogether  different  type  from  that  of 
subject "  B. "  Subject "  S "  seldom  perspires  freely.  Cold 
bathing,  if  continued  for  any  length  of  time,  makes  him 
blue  all  over  and  sets  up  actual  rigours  which  last  for 
some  time.  With  subject  "B"  cold  bathing  causes  the 
usual  reaction,  i.e.,  tonic  hypersemia  with  the  glowing 
skin  and  general  sense  of  well-being  that  accompanies  it. 
Here  is  another  indication  of  the  necessity  of  closely  study- 
ing the  circulatory  mechanism  in  every  individual  be- 
fore recommending  cold  procedures  in  hydrotherapy. 

August  3d. — In  the  early  part  of  the  day  the  weather 
was  somewhat  warmer,  the  temperature  in  the  cabin  being 
74°  F.  at  7.47  a.m.  The  port-holes  were  open,  but  the 
cabin  was  on  the  leeward  side  and  there  was  no  fresh  breeze 
blowing  in.  The  effect  upon  the  circulation  is  shown  in 
protocol  26.  The  effects  of  the  cool  night  are  well  shown. 
Subject  "B"  felt  very  well  all  day. 

August  4th. — On  this  day  the  weather  was  cool,  but 
wet  and  windy.  There  was  little  motion  to  the  l3oat. 
The  port-holes  were  closed  all  night  on  account  of  rain. 
The  effect  upon  the  circulation  is  shown  in  protocol  26. 
The  subject  felt  well  all  day. 

August  5th. — On  awakening  the  ship  was  lying  in 
New  York  Harbour.  Subject  "B"  felt  well  in  every  way. 
The  temperature  in  the  cabin  was  71  °  F.,  but  the  air  was 
"stuffy."  The  effect  upon  the  circulation  is  shown  in 
protocol  26. 

At  8  a.m.  the  passengers  were  landed  in  New  York. 


CHAPTER  XXVIII 

STUDIES  IN  SEASICKNESS    (Continued) 

So  far  the  experiments  had  shown  that  atropin  in 
eombination  with  strychnin  is  very  effective  in  overcom- 
ing the  chief  disagreeable  symptoms  of  seasickness.  It 
was,  however,  apparent,  notwithstanding  the  subjective 
sense  of  well-being,  that  the  gastric  functions  were  any- 
thing but  normal.  An  effort  was  therefore  made  to  find 
some  means  w^hereby  the  good  effects  of  atroj^in  and 
strychnin  might  be  supplemented,  the  special  object  in 
view  being  improvement  in  gastric  secretion,  absorption 
and  motility.  A  series  of  experiments  was  undertaken 
in  which  decoctions  of  the  mucous  membrane  of  the 
duodenum,  and  of  the  pylorus  and  other  regions  of  the 
stomach,  made  after  the  manner  described  by  Bayliss  and 
Starling  ^^  and  by  Edkins,^^  ^ere  thoroughly  tested  by 
means  of  rotations.  These  experiments  belong  to  a 
separate  series  and  are  detailed  elsewhere.  The  results, 
however,  warranted  a  trial  of  the  decoctions  in  seasick- 
ness. Accordingly  several  sea-trips  were  undertaken  with 
this  object  in  view.  Each  of  the  three  subjects  used  for 
the  purpose  of  this  study  had  been  a  long  time  under 
observation.  Numerous  test  meals  had  been  given  to 
each  on  various  occasions,  so  that  the  condition  of  the 
stomach  in  each  as  regards  secretion,  absorption  and 
motility  was  thoroughly  understood.  During  these  tests 
observations  of  the  pulse-rate  and  blood-pressure  were  also 
made  as  well  as  a  study  of  the  changes  occurring  in  the 
retinal  vfjssels  during  the  milder  fonns  of  seasickness. 

On  November  8,  1910,  a  trip  lasting  about  nine  hours 
was  made  upon  the  steamship  Angler.  The  weather  was 
fair,  but  on  the  outward  leg  of  the  trip  the  boat  pitched 
and  rolled  just  enough  to  excite  in  all  three  subjects  some 
of  the  milder  symptoms  of  seasickness.     During  a  period 

384 


SEASICKNESS  385 

when  the  boat  was  at  anchor  the  rolling  was  so  bad  that 
one  of  the  subjects,  "B,"  became  very  sick  and  succeeded 
in  retaining  his  test  meal  for  the  accustomed  hour  only  by 
remaining  absolutely  quiet  and  exercising  all  the  self- 
control  at  his  command. 

Subject  "C"  had  an  instillation  of  homatropin  in  the 
right  eye  and  the  retinal  vessels  were  studied  with  the 
ophthalmoscope  at  the  commencement  of,  and  several  times 
during,  the  trip.  As  the  boat  started  at  8.20  a.m.  the 
retinal  veins  and  arteries  were  somewhat  constricted,  the 
veins  being  slightly  larger  than  the  arteries.  The  blood- 
pressure  at  this  time  was  145  and  the  pulse-rate  92.  At 
8.52  the  retinal  vessels  appeared  to  be  slightly  smaller, 
the  white  line  of  the  arteries  being  more  marked,  although 
the  retina  as  a  whole  was  not  very  pale.  The  pupil  was 
well  dilated  and  yet  some  difficulty  was  experienced  in 
studying  the  fundus  at  this  period,  because  of  the  boat's 
motion  and  the  unsteadiness  of  the  candle-flame,  an  added 
factor  being  perhaps  some  slight  changes  in  the  refractive 
mechanisms.  The  blood-pressure  at  this  time  was  120 
and  the  pulse-rate  76.  At  11.52  the  retinal  veins  were 
dilated  as  compared  with  the  arteries  which  were  very 
small.  The  retina  looked  paler  than  previously.  The 
subject  felt  "a  little  queer  in  the  head,"  i.e.,  heavy  and 
groggy.  At  11.21  the  blood-pressure  was  185  and  the 
pulse-rate  84.  This  subject  "C"  has,  in  the  receptors 
or  afferent  arcs  related  to  his  horizontal  semicircular 
canals  a  certain  degree  of  insensitiveness  to  aural  irriga- 
tions, rotations  and  galvanism.  This  was  manifested  on 
numerous  occasions  in  experimental  tests.  It  was  there- 
fore a  matter  of  interest  to  find  that,  on  this  trip  as  he 
sat  with  the  coronal  plane  parallel  to  the  long  axis  of  the 
boat,  the  rolling  motion  (through  his  superior  and  pos- 
terior canals)  so  weakened  him  during  the  period  that 
the  boat  lay  at  anchor  that  he  could  scarcely  stand. 
This  weakness  was  accompanied  by  nausea,  vertigo  and 
nystagmus,  the  latter  being  vertical  toward  the  feet  and 
accompanied  by  an  apj^arent  movement  of  external  objects 
"away  from  him  in  front."  At  8.32  an  Ewald  meal  was 
given  upon  the  fasting  stomach  and  removed  at  9.82.  The 
chyme  returned  was  siv  and  contained  a  little  fresh  blood. 
At  10.16  a  decoction  of  pig's  pyloric  mucous  membrane, 


386  SEASICKNESS 

representing  J  of  the  yield  of  four  stomachs,  was  given  in 
its  purity  j^er  os  and  followed  by  a  few  sips  of  water. 
At  10.25  an  Ewald  meal  was  given  in  which  allowance 
was  made  for  the  fluid  taken  as  pyloric  decoction  and  as 
the  mouth  rinser  that  followed  it.  At  11.28  the  stomach 
contents  were  withdrawn,  the  amount  of  chyme  being  siv^. 
With  this  meal  the  K  I  absorption  test  reacted  for  iodin 
in  the  mouth  at  10.44,  i.e. ,  in  nineteen  minutes.  The  salol 
test  showed  no  reaction  within  the  hour  and  only  a  feeble 
reaction  at  11.43. 

Analysis  showed  for  the  fii'st  meal:  total  acidity, 
.343%  by  wt.,  free  HCl,  .211,  combined  HCl,  .102;  and 
for  the  second  meal:  total  acidity,  .284,  free  HCl,  .226, 
combined  HCl,  .036. 

The  amount  of  free  HCl  after  these  two  meals  was 
unusual  for  the  subject,  who  under  somewhat  similar  cir- 
cumstances, i.e.,  in  rotations  generally  showed  free  HCl 
diminished  or  absent.  As  the  subject  had  been  up  early 
and  had  had  no  food  before  8.32  a.m.,  it  is  presumed  that 
the  resting  state  of  the  gastric  glands  coupled  with  normal 
hunger  had  something  to  do  with  the  production  of  so 
much  free  HCl  in  the  first  meal,  whilst  in  the  second  meal 
the  high  percentage  of  free  HCl  might  perhaps  be  attributed 
in  part  to  the  pyloric  decoction. 

The  latter  assumption,  however,  gains  no  support  from 
the  results  of  the  test  meals  given  to  the  other  subjects 
*'B  and  S"  in  whom  there  was  no  distinct  increase  of 
free  HCl  in  the  test  meals  following  the  administration  of 
pyloric  extract.  It  is  possible  that  in  this  test  some  of 
the  gastric  contents  from  the  previous  meal  remained  in 
the  stomach,  as  there  is  no  mention  in  the  notes  of  the 
stomach  having  been  irrigated  after  removal  of  the  first 
Ewald  meal. 

Analysis  of  specimen  taken  Nov.  8th  on  the  Angler  from  sub- 
ject "C."  Ingested  at  8.30  a.m.  an  Ewald  breakfast.  Re- 
moved at  9.32.  Amount  of  chyme,  siv.  Resorcin  test 
showed  the  presence  of  free  HCl. 

Tot.  acidity,    94,  or. 343%  by  Tot.  HCl,  86,  or  .313%  by  wt. 

wt.  Acid  salts,  8,  or  .029%  by  wt. 
Free  HCl,  58,  or  .211%  by  wt. 

Comb'd  HCl,    28,  or  .102%  by  Lactic  acid,  trace. 

wt.  Starch  J  absent. 


SEASICKNESS  387 

Amylodextrin,  trace.  Peptones,  present. 

Erythrodextrin,  present.  Enzymes,  normal. 

Achroodextrin,  present.  Bile,  absent. 

Maltose,  present.  Mucus,  small  amount. 

Albumin,  trace.  Blood,  present. 

Note.  A  small  amount  of  fresh  blood  came  with  the  last  of 
the  stomach  contents. 

Analysis  of  specimen  taken  Nov.  8th  on  board  the  Angler  from 
subject  "C. "  Ingested  at  10.25  a.m.  an  Ewald  test  meal  fol- 
lowing- the  administration  pe?-  os  of  pyloric  extract  at  10.16. 
Withdrawn  at  11.28.  Amount  of  chyme,  §iv.  The  chyme 
contained  a  few  old  blood-stained  shreds  but  no  free  blood. 
Resorcin  test  showed  the  presence  of  free  HCl. 

Tot.  acidity,    78,  or  .284%  by  Achroodextrin,  present. 

wt.  Maltose,  present. 

Free  HCl,  62,  or.  226%  by  wt.  Albumin,  trace. 

Comb'd  HCl,    10,  or  .036%  by  Peptones,  present. 

wt.  Bile,  absent. 

Tot.  HCl,  72,  or  .262%  by  wt.  Mucus,  very  little. 

Acid  salts,  6,  or  .021%  by  wt.  Blood,  absent. 

Coagulating  enzymes,  normal. 

Lactic  acid,  trace.  Peptonizing  enzymes  (pepsin). 
Starch,  absent.  subnormal. 

Amylodextrin,  trace.  Peptonizing    zymogens    (pep- 
Erythrodextrin,  present.  sinogen),  subnormal. 

Note.  The  test  for  pepsin  and  pepsinogen  showed  a  poor 
degree  of  digestion  as  compared  with  the  controls. 

The  tests  made  with  subject  "B"  on  board  the  Angler 
November  8th  were  as  follows:  The  subject  arose  at  5  a.m. 
and  had  breakfast  at  5.80,  consisting  of  6  oz.  of  bread  with 
butter,  2  boiled  eggs  with  butter  4  oz. ,  and  two  cups  of 
weak  tea  with  milk  and  sugar.  At  7.56  whilst  the  boat 
was  still  at  the  wharf  the  blood-pressure  was  140  and  the 
pulse-rate  96.  This  condition  of  the  circulation  was  due 
to  the  heavy  choppy  motion  of  the  boat,  which  caused 
marked  dizziness  in  this  susceptible  subject.  A  few  mo- 
ments later  the  subject  was  sweating  and  the  face  and 
ears  were  flushed.  At  this  time  the  blood-pressure  and 
pulse-rate  were  90  and  96  respectively.  The  cabin  was 
warm  and  stuffy  and  the  odour  of  bilge  water  extremely 
offensive.  At  8.20  the  boat  started.  During  the  first 
part  of  the  journey  the  boat  was  fairly  steady,  but  the  air  in 
the  cabin  was  bad  and  affected  the  subject  considerably. 
The  vibration  of  the  machinery  was  also  annoying.     The 


388  SEASICKNESS 

subject  had  a  slight  occipital  ache  with  a  sense  of  fulness 
in  the  head.  The  face  was  flushed  and  hot.  The  sight 
of  the  water  rushing  past  the  boat  caused  distress.  There 
was  nausea  accompanied  by  chilly  sensations  along  the 
spine.  The  subject  sat  with  the  coronal  plane  parallel  to 
the  long  axis  of  the  boat.  At  9.08  the  blood-pressure  was 
140  and  the  pulse-rate  96.  The  subject  at  this  time  was 
sitting  in  his  shirt-sleeves  in  the  path  of  a  cool  breeze 
from  an  open  door.  He  felt  weak  and  nervous  all  over. 
There  was  some  nausea  coupled  with  a  slight  "lump- 
sensation"  in  the  stomach  and  a  sickening  heavy  ache 
all  through  the  head  {dolor  cerebri).  Light  was  annoying 
to  the  eyes  whilst  noise  of  any  sort  was  distinctly  unpleas- 
ant. Psychic  depression  was  marked.  The  boat  rolled 
constantly,  the  movements  being  short  and  abrupt.  At 
10.01  the  blood-pressure  was  140  and  the  pulse-rate  84. 
At  10.50,  after  removal  of  its  contents,  the  stomach  was 
irrigated.  The  chyme  amounted  to  |  iii  and  contained 
much  mucus  and  a  few  old  blood-stained  shreds.  At  this 
time  (11.07)  the  boat,  lying  at  anchor,  rolled  very  much. 
At  11.11  pyloric  extract  equivalent  to  \  of  the  yield  of  four 
stomachs  was  given  per  os.  This  was  followed  by  an 
Ewald  test  meal  at  11. 16  as  in  the  case  of  subject "  C. "  At 
11.22  the  subject  felt  heavy  and  wretched,  the  head  ached, 
the  face  was  flushed  and  warm,  and  the  feet  were  cold. 
At  11.35  the  blood-pressure  was  140  and  the  pulse-rate 
76.  At  11.42  the  subject  felt  a  slight  "lump-sensation" 
in  the  stomach  toward  the  left  of  the  epigastrium  and 
with  this  a  "groggy,  drunken  heaviness"  in  the  head. 
The  boat  was  still  at  anchor  but  rocking  in  a  distressing 
manner.  At  11.53  the  subject  felt  nauseated  and  sick. 
The  lump-sensation  was  present  in  the  stomach,  and  the 
face  was  flushed.  A  moment  later  the  subject  was  on  the 
verge  of  vomiting;  the  skin  became  pale  and  broke  out  in 
sweat.  At  12. 05  the  blood-pressure  was  145  and  the  pulse- 
rate  76.  The  subject  was  still  sweating,  and  very  sick. 
Long  deep  breaths  were  frequently  taken,  the  subject's 
weakness  was  extreme  and  he  experienced  a  sense  of  suffo- 
cation as  if  "smoke  were  in  the  lungs  preventing  the 
entrance  of  the  air. "  There  were  signs  of  marked  irrita- 
bility of  temper  which  was,  however,  to  a  great  extent 
controlled,    After  a  few  minutes  the  attack  passed  off.    The 


SEASICKNESS  889 

subject's  face  assumed  a  better  color;  the  feet  became 
warm,  but  the  muscles  were  still  very  tremulous  and  weak. 
The  respirations  just  after  the  attack  were  from  twelve  to 
fourteen  to  the  minute. 

It  will  be  noted  that  all  through  the  above  attack  there 
was  marked  physical  and  psychic  depression  and  yet  the 
blood-pressure  was  high  for  this  subject,  i.e.,  145  as  com- 
pared with  the  normal,  which  for  him  is  about  110.  The 
pulse-rate  was  also  remarkable  in  being  rather  slow,  76  as 
compared  with  the  normal  which  averages  for  this  subject 
88  to  92.  More  remarkable  still  was  the  fact  that  at  no  time 
was  there  any  gagging  or  contraction  of  the  abdominal 
muscles.  These  observations  show  that  lowered  blood- 
pressure  is  not  necessarily  associated  with  the  extreme 
sense  of  weakness  that  precedes  vomiting.  This  fact,  how- 
ever, must  not  be  interpreted  as  meaning  that  everything 
goes  well  with  the  circulation  in  the  pre-vomiting  stage. 
On  the  contrary;  for  whilst  the  peripheral  vascular  con- 
striction with  slowed  heart-rate  (both  being  the  direct 
result  of  medullaiy  irritation)  may  suffice  to  maintain  a 
high  blood-pressure  yet  the  volume  of  the  heart's  output 
is  so  small  in  any  given  period  that  medullary  anemia 
ensues.  This  latter  condition  may,  to  a  great  extent,  be 
relieved  by  recumbency  but  nature  has  a  most  effective 
way  of  meeting  it  by  vomiting  which  rids  the  subject  of 
one  of  the  powerful  (secondary)  causes  of  medullary  irri- 
tation, viz.,  the  gastric  contents,  and  at  the  same  time  pro- 
motes the  flow  of  abdominal  blood  toward  the  heart,  i.e., 
raises  the  blood-pressure  by  mechanical  means  thereby 
obviating,  to  some  extent,  the  necessity  for  extreme  pe- 
ripheral arterial  constriction.  Without  entering  into  a  dis- 
cussion as  to  the  mechanism  of  shock,  i.e.,  as  to  whether 
shock  is  due  to  arterial  relaxation  (Crile)  or  to  arterial 
constriction  (Porter),  or  to  venous  relaxation  (Hender- 
son), it  can  be  safely  said  that  the  end  result  of  the  vom- 
iting is  the  same,  viz.,  the  supply  of  a  greater  volume  of 
blood  to  the  medullary  centres  with  less  effort  on  the  part 
of  the  cardiovascular  system. 

At  12. 18  the  stomach  contents  were  removed  by  vomit- 
ing. The  amount  of  chyme  recovered  was  sixss.  It  con- 
tained a  moderate  amount  of  mucus,  and  a  few  old  blood- 
stained scales.     The  salol,  which  had  been  administered 


390  SEASICKNESS 

in  a  gelatine  capsule  at  the  end  of  the  meal,  was  vomited 
as  a  moist  mass  but  intact,  just  as  it  had  been  swallowed, 
only  minus  the  capsule.  Owing  to  this  fact  in  all  subse- 
quent experiments  the  salol  was  administered  at  the  be- 
ginning of  the  test  meals  instead  of  at  the  end  as  in  pre- 
vious tests. 

Immediately  after'vomiting,  the  subject  felt  ver}'-  much 
better.  At  12. 37  the  blood-pressure  was  140  and  the  pulse- 
rate  76.  The  subject  at  this  time  was  feeling  fairly  well 
but  he  had  a  slight  headache  and  was  very  weak.  As 
soon,  however,  as  the  boat  weighed  anchor  and  got  under 
steam  the  cool  air  benefited  him  very  much.  At  6  p.m. 
the  urine  was  normal.  There  was  no  evidence  of  albu- 
min, sugar,  or  glycuronic  acid. 

Analysis  of  specimen  taken  Nov.  8th  on  board  the  Angler  from 
subject  "B."  Ingested  at  5.30  a.m. — breakfast  consisting 
of  2  soft-boiled  eggs  with  4  oz.  of  butter ;  2  cups  of  weak 
tea  with  milk  and  sugar  and  6  oz.  of  bread  with  2  oz.  of 
butter.  Removed  at  10.50.  The  chyme  was  3  iii  in  amount 
and  contained  much  thick  mucus  with  a  few  tiny,  old,  blood- 
stained scales.  Resorcin  test  showed  absent  or  very  great- 
ly diminished  free  HCl. 

Tot.  acidity,    32,  or  .116%  by  Maltose,  present. 

wt.  Albumin,  present. 

Free  HCl,  6,  or.  021%  by  wt.  Peptones,  faint  trace. 

Comb'd  HCl,    20,  or  .073%  by  Coagulating  enzymes  (chymo- 

wt.  sin),  present. 

Tot.  HCl,  26,  or  .094%  by  wt.  Peptonizing  enzymes  (pepsin). 
Acid  salts,  6,  or  .021%  by  wt.  diminished  or  absent. 

Lactic  acid,  present.  Peptonizing  zymogen  (pepsin- 
Starch,  absent.  ogen),  present. 

Amylodextrin,  absent.  Bile,  absent. 

Erythrodextrin,  absent.  Mucus,    considerable  amount. 

Achroodextrin,  absent.  Blood,  absent. 

Note.  There  was  no  evidence  of  gross  fat  in  the  chyme.    Ab- 
sorption and  motility  tests  not  made. 

Analysis  of  specimen  taken  Nov.  8th  on  board  the  Angler  from 
subject  "B."  Ingested  at  11.16  a.m.  an  Ewald  breakfast, 
preceded  at  11.11  by  pyloric  extract  given  per  os  and 
representing  J  of  the  yield  of  4  stomachs.  Removed  by 
vomiting  at  12.16.  The  chyme  amounted  to  ?ixss  and  con- 
tained a  moderate  amount  of  mucus  with  a  few  old,  blood- 
stained scales.  Resorcin  test  showed  absent  or  considerably 
diminished  free  HCl. 


SEASICKNESS  391 

Tot.  acidity,   26,  or  .094%  by  Achroodextrin,  present. 

wt.  Maltose,  present. 

Free  HCl,    6,  or  .021%  by  wt.  Albumin,  present. 

Comb'd  HCl,    14,  or  .051%  by  Peptones,  faint  trace. 

wt.  Peptonizing  enzymes  (pepsin) ^ 
Tot.  free  HCl,  20,  or  .073%  by  diminished  or  absent. 

wt.  Peptonizing  zymogens  (pep- 
Acid  salts,  6,  or  .021%  by  wt.  sinogen),  present. 

Coagulating  enzymes  (chymo- 
Lactic  acid,  trace.  sin),  present. 

Starch,  absent.  Bile,  absent. 

Amylodextrin,  absent.  Mucus,  moderate  amount. 

Erythrodextrin,  trace.  Blood,  absent. 

The  K  I  absorption  test  showed  iodin  in  the  saliva  in  17 
minutes.  The  salol  (motility)  test  did  not  react  within  the 
hour. 

Experiments  made  November  8th  on  board  the  Angler 
upon  subject  "S."  At  8.09  a.m.  the  blood-pressure  was 
135  and  the  pulse-rate  76.  At  this  time  the  boat  was  be- 
side the  pier,  and  rocking  very  nuich.  At  8.20  the  boat 
started,  and  at  8.42  an  Ewald  meal  was  given  upon  the 
fasting  stomach.  At  8.54  the  boat  was  fairly  steady.  The 
blood-pressure  at  this  time  was  140,  and  the  i3ulse-rate  72. 
At  9.25  the  blood-pressure  was  130  and  the  pulse-rate  72. 
At  9.42  the  stomach  contents  were  removed.  The  ch}Tne 
amounted  to  siiif,  and  contained  nothing  abnormal. 
During  the  journey  so  far,  the  boat  had  behaved  fairly 
well.  It  pitched  and  rolled  a  little,  however,  just  enough 
to  cause  disagreeable  symptoms  in  subjects  "B"  and 
"C." 

At  9.55  atropin  sulphate,  gr  1/50,  was  administered 
h}^odermically.  At  10.28  the  blood-pressure  was  130 
and  the  pulse-rate  104.  The  rapid  pulse,  a  very  unusual 
thing  in  this  subject,  represents  the  atropin  effect  upon 
the  vagus  terminals  in  the  heart.  The  boat  was  rolling 
somewhat  at  this  period.  At  10. 33  pyloric  extract,  equiva- 
lent to  ^  of  the  yield  of  4  stomachs,  was  given  per  os. 
At  10.44  an  Ewald  test  meal  was  given.  At  11.30  the 
blood-pressure  was  135,  and  the  pulse-rate  92.  At  11.42 
the  stomach  contents  were  removed.  The  chyme  amounted 
to  3VSS  and  contained  nothing  abnormal.  During  the 
time  that  the  test  meal  was  retained  the  subject  complained 
of  no  disagreeable  feelings  although  the  boat  rocked  con- 


392  SEASICKNESS 

siderably  as  she  lay  at  anchor.  At  11.53  there  was  heavi- 
ness over  the  eyes.  Otherwise  the  subject  felt  well.  At 
11.48  the  blood-pressure  was  125  and  the  pulse-rate  80. 

Analysis  of  specimen  taken  Nov.  8th  on  board  the  Angler  from 
subject  "S."  Ingested  at  8.42  a.m.  an  Ewald  breakfast. 
Removed  at  9.42.  The  chyme  was  §  iii^  in  amount  and  con- 
tained nothing  abnormal  macroscopically.  Resorcin  test 
showed  the  presence  of  free  HCl. 

Tot.  acidity,    80,  or  .292%  by  Amylodextrin,  present. 

wt  Erythrodextrin,  present. 

Free  HCl,  54,  or  .197%  by  wt.  Maltose,    no  marked  reaction. 

Comb'd  HCl,    16,  or  .058%  by  Albumin,    faint  trace. 

wt.  Peptones,  present. 

Tot.  HCl,  70,  or  .255%  by  wt.  Enzymes,  normal. 

Acid  salts,  10,  or .  036%  by  wt.  Bile,  absent. 

Lactic  acid,  trace.  Mucus,  no  excess. 

Starch,  absent.  Blood,  absent. 

Absorption  and  motility  tests  not  made. 

Analysis  of  specimen  taken  Nov.  8th  on  board  the  Angler  from 
subject  "S."  Ingested  at  10.44  a.m.  an  Ewald  test  meal, 
preceded  by  atropin  sulphate,  gr  1/50  hypodermically,  at 
9.55,  and  pyloric  extract  per  os  equivalent  to  J  of  the  yield 
of  4  stomachs  at  10.33.  Removed  at  11.44.  The  chyme 
amounted  to  §vss  and  contained  nothing  abnormal  macro- 
scopically.   Resorcin  test  showed  the  presence  of  free  HCl. 

Tot.  acidity,    54,  or  .197%  by  Achroodextrin,  present. 

wt.  Maltose,  present. 

Free  HCl,  26,  or  .094%  by  wt.  Albumin,  faint  trace. 

Comb'd  HCl,    22,  or  .080%  by  Peptones,  present. 

wt.  Peptonizing  enzymes  (pepsin), 
Tot.  HCl,  48,  or  .174%  by  wt.  diminished. 

Acid  salts,  6,  or  .021%  by  wt.  Peptonizing    zymogens    (pep- 
sinogen), diminished. 

Lactic  acid,  trace.  Coagulating  enzymes,  normal. 

Starch,  absent.  Bile,  absent. 

Amylodextrin,  present.  Mucus,  no  excess. 

Erythrodextrin,  present.  Blood,  absent. 

The  K  I  absorption  test  showed  iodin  in  the  saliva  in  19 
minutes.  The  salol  test  showed  no  reaction  within  the  hour. 
The  pyloric  extract  used  in  the  tests  made  on  November  8th  had 
been  made  some  weeks  and  might  therefore  have  undergone 
oxidation  which  seems  to  render  it  inert. 

On  November  20th  another  trip,  lasting  about  eight 
hours,  was  made  on  the  Angler.     On  this  occasion  tests 


SEASICKNESS  393 

were  made  upon  the  same  subjects  as  in  the  previous  ex- 
periments. As  Edkins  ^^  has  shown  on  animals  that  atropin 
does  not  affect  the  action  of  pyloric  secretogogues,  the 
action  of  this  drug  in  conjunction  with  extracts  of  gastric 
mucous  membrane  was  studied  in  subjects  "  B"  and  "  C, " 
whilst  in  subject  "S"  the  effect  of  the  extracts  alone,  i.e., 
without  atropin  was  observed.  The  blood-pressure  and 
pulse-rate  and  the  general  symptoms  were  also  studied.  In 
subject  "C"  the  condition  of  the  retinal  vessels  was 
studied. 

Observations  made  November  20th  on  subject  "C." 
At  3.30  a.m.  two  glasses  of  diluted(half  and  half)  milk 
were  taken.  At  6.30  one  cup  of  water  was  taken  and 
another  at  7.  The  bowels  moved  rather  freely  at  6.30, 
6.35  and  7.  These  movements  were  the  result  of 
cathartics  taken  on  the  previous  day.  At  8  a.m.,  after 
boarding  the  Angler^  the  blood-i)ressure  was  140  and  the 
pulse-rate  100.  The  boat  started  at  8.07.  At  8.27  an 
instillation  of  homatropin  was  given  in  the  right  eye. 
At  8.42  the  retinal  arteries  were  about  normal  in  size  and 
of  a  slightly  greyish  color.  The  veins  were  somewhat 
larger  than  the  arteries  and  of  a  dull  red  hue.  The  fundus 
as  a  whole  was  of  a  rich  red  colour.  The  boat  was  going 
steadily — no  motion  being  manifested  beyond  the  vibra- 
tion from  the  engines.  At  8.53  an  Ewald  meal  was  given. 
At  9.07  the  blood-pressures  were  140,  145,  140,  140,  with 
corresponding  pulse-rates  of  100,  96,  100,  100.  The  boat 
was  pitching  and  rolling  somewhat  at  this  period.  At 
9.35  the  blood-pressure  and  pulse-rate  were  135  and  100 
respectively.  At  9.40  the  retinal  vessels  were  about  the 
same  as  when  observed  at  8.42.  Just  after  the  ophthal- 
moscopic examination  of  the  eye  the  blood-pressure  and 
pulse-rate  were  135  and  96.  At  9.53  the  stomach  con- 
tents were  removed.  Thech^^me  was  siiij  in  amount  and 
contained  a  moderate  amount  of  mucus  and  a  few  old 
blood-stained  scales.  After  removal  of  its  contents  the 
stomach  was  irrigated.  At  10.25  atropin  sulphate,  gr  1/50, 
was  given  hypodermically.  At  this  time  the  boat  was 
rolling  and  pitching  somewhat,  and  the  subject,  who  was 
sitting  with  the  coronal  plane  parallel  to  the  long  axis  of 
the  boat,  felt  a  little  distress  in  the  head.  At  10.47  the 
subject  received,  per  os,  extracts  from  the  gastric  mucous 


394     .  SEASICKNESS 

membrane  of  the  pig  (fundic  and  intermediate  portions), 
each  portion  representing  J  of  the  yield  of  four  stomachs. 
The  bulk  of  the  extracts  was  i^Y.  At  11.04  the  boat  was 
rolling  considerably.  The  blood-pressiire  and  pulse-rate 
were  140  and  116  respectively.  The  pulse-rate  evidently 
indicated  the  atropin  effect  upon  the  cardiac  vagus  termi- 
nals. 

At  11.19  the  boat,  lying  at  anchor,  rolled  considerably 
and  made  the  subject  feel  heavy  and  sleepy.  At  11.20 
the  retinal  arteries  were  distinctly  smaller,  whilst  the  veins 
were  comparatively  larger  and  darker.  The  fundus  as  a 
whole  seemed  paler  than  in  previous  observations.  At 
11.82  an  Ewald  test  meal  was  given  and  removed  at  12.82 
p.m.  The  ch}Txie  was  Jiii  in  amount  with  no  abnormal 
macroscopic  contents.  The  K  I  absorption  test  showed 
iodin  in  the  saliva  in  15  minutes.  The  salol  test  showed 
a  feeble,  unreliable  reaction  at  12.80  but  was  distinctly 
positive  at  1.  From  12.89  to  12.42  the  blood-pressures 
were  145,  145,  145,  145,  with  corresponding  pulse-rates  of 
88,  88,  96,  92. 

At  2  p.m.  the  retinal  arteries  were  not  so  small  as  in 
the  previous  observations;  the  veins  were  a  trifle  larger 
than  the  arteries. 


Analysis  of  specimen  taken  Nov.  20th  on  board  the  Angler  from 
subject  "C."  Ingested  at  8.53  a.m.  an  Ewald  meal.  Re- 
moved at  9.53.  Amount  of  chyme,  siiij.  No  abnormal  mac- 
roscopic contents.  Resorcin  test  showed  the  presence  of 
free  HCl 

Tot.  acidity,    70,  or  .255%  by  Amylodextrin,  present. 

wt.  Erythrodextrin,  present. 

Free  HCl,  50,  or  .182%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,    14,  or  .051%  by  Maltose,  present. 

wt.  Albumin,  absent. 

Tot.  HCl,  64,  or  .233%  by  wt.  Peptones,  present. 

Acid  salts,  6,  or  .021%  by  wt.  Enzymes,  normal. 

Bile,  absent. 

Lactic  acid,  trace.  Mucus,  no  excess. 

Starch,  absent.  Blood,  absent. 

Note.  The  high  percentage  of  free  HCl  in  this  meal,  a  very 
unusual  thing  for  this  subject,  may  be  in  part  the  result  of  the 
milk  taken  in  the  early  morning,  the  products  of  digestion  which 
lingered  in  the  stomach  acting  as  gastric  secretogogues. 


SEASICKNESS  395 

Analysis  of  specimen  taken  Nov.  20th  on  board  the  Angler 
from  subject  "C."  Ingested  at  11.32  a.m.  an  Ewald  meal, 
after  atropin  sulphate,  gr  150  hypodermically,  at  10.25,  and 
intermediate  and  fundic  extracts  representing  for  each  por- 
tion J  of  the  yield  of  4  stomachs  given  per  os  at  10,47. 
Withdrawn  at  12.32  p.m.  Amount  of  chyme,  ^iii.  No  ab- 
normal macroscopic  contents.  Resorcin  test  showed  the 
presence  of  free  HCl. 

Tot.  acidity,    54,  or  .197%  by      Amylodextrin,  trace, 
wt.  Erythrodextrin,  present. 

Free  HCl,  40,  or  .146%  by  wt.      Achroodextrin,  present. 

Comb'd  HCl,    10,  or  .036%  by      Maltose,  present, 
wt.  Albumin,  absent. 

Tot.  HCl,  50,  or  .182%  by  wt.      Peptones,  present. 

Acid  salts,    4,  or  .014%by  wt.      Enzymes,  normal. 

Bile,  absent. 

Lactic  acid,  trace.  Mucus,  no  excess. 

Starch,  absent.  Blood,  absent. 

Such  a  percentage  of  free  HCl  as  shown  in  the  above  analy- 
sis never  occurred  in  this  subject  before  under  similar  circum- 
stances, except  in  the  tests  of  November  8th,  when  it  resulted 
probably  from  secretogogues  retained  in  the  stomach  from  the 
previous  meal.  This,  coupled  with  the  fact  that  in  the  tests 
made  upon  subjects  "B"  and  "S"  there  was  unusual  and  marked 
increase  of  the  free  HCl,  led  to  the  supposition  that  the  in- 
creased production  of  free  HCl  may  have  been  the  direct  result 
of  the  gastric  extracts. 

The  tests  made  on  subject  "S,"  November  20th,  were 
as  follows :  The  air  was  rather  cold  and  sharp  as  the  A  ngJer 
was  boarded.  At  8.07  a.m.  the  boat  started.  The  blood- 
pressure  and  pulse-rate  at  8.10  were  115  and  80  respec- 
tively and  at  8.13,  125  and  SS.  The  boat  had  rocked 
rather  freely  at  the  pier  but  was  fairly  steady  after  the 
start.  At  8.58  an  Ewald  breakfast  was  given.  The 
weather  was  fine  and  ever}i;hing  looked  merry  in  the  bright 
sunlight.  At  9.08  the  blood-pressure  and  pulse-rate  were 
115  and  72  respectively.  At  9.58  the  stomach  contents 
were  removed  and  the  stomach  irrigated.  The  amount  of 
chyme  recovered  w^as  3ii  with  nothing  abnormal  macro- 
scopically.  At  10.44  the  subject  received,  j^er  os,  extract 
of  fundic  and  intermediate  mucous  membrane  each  por- 
tion representing  ^  of  the  yield  of  four  stomachs.  The 
bulk  of  the  extract  was  £3 v.  At  11  the  boat  was  rolling 
a  little  and  the  blood-pressure  and  pulse-rate  were  110  and 
72  respectively.  At  11.19  an  Ewald  test  meal  was  given. 
At  this  time  the  boat  was  lying  at  anchor  and  rolling  with 


896  SEASICKNESS 

sickening  effect.  At  11.20  the  stomach  contents  were 
removed.  The  chyme,  which  was  3  iii  in  amount,  con- 
tained nothing  abnormal  macroscopically.  At  12.46  the 
blood-pressure  and  pulse-rate  were  115  and  QS  respectively. 
The  subject  experienced  no  marked  disagreeable  effects 
from  the  trip.  After  going  home  he  had  several  loose 
movements  from  the  bowels. 

Analysis  of  specimen  taken  Nov.  20th  on  board  the  Angler  from 
subject  "S."  Ingested  at  8.58  a.m.  an  Ewald  breakfast. 
Withdrawn  at  9.58.  Chyme  amount  3  ii.  Nothing  abnormal 
macroscopically.  Resorcin  test  showed  the  presence  of 
free  HCl. 

Tot.  acidity,    88,  or  .321%  by      Amyioaextrin,  trace. 

wt.  Erythrodextrin,  present. 

Free  HCl,  64,  or  .233%  by  wt.      Achroodextrin,  present. 
Comb'd  HCl,  16,  or  .058%  by      Maltose,  trace. 

wt.  Albumin,  absent. 

Tot.  HCl,  80,  or  .292%  by  wt.      Peptones,  present. 
Acid  salts,  8,  or  .029%  by  wt.      Enzymes,  normal. 

Bile,  absent. 
Lactic  acid,  trace.  Mucus,  no  excess. 

Starch,  absent.  Blood,  absent. 

Absorption  and  motility  tests  not  made. 

Note.  The  high  percentage  of  free  HCl  shown  above,  is  un- 
usual for  this  subject  and  may,  perhaps,  be  explained  by  the 
resting  state  of  the  glands  and  the  long  fast.  Ordinarily  the 
subject  eats  breakfast  at  5.30  a.m.,  whereas  in  this  test  the  first 
food  was  taken  at  8.58  a.m. 

Analysis  of  specimen  taken  Nov.  20th  on  board  the  Angler 
from  subject  "S."  Ingested  at  11.19  a.m.  an  Ewald  meal. 
The  subject  had  received,  per  os,  at  10.44  extract  of  fundic 
and  intermediate  mucous  membrane,  each  part  representing 
J  of  the  yield  of  4  stomachs.  Withdrawn  at  12.20  p.m. 
Amount  of  chyme,  ^iii.  Nothing  abnormal  macroscopically. 
Resorcin  test  showed  the  presence  of  free  HCl. 
Tot.  acidity,    94,  or  .343%  by      Amylodextrin,  trace. 

wt.  Erythrodextrin,  present. 

Free  HCl,  72,  or  .262%  by  wt.      Achroodextrin,  present. 
Comb'd  HCl,    20,  or  .073%  by      Maltose,  present, 
wt.  Albumin,  absent. 

Tot.  HCl.  92,  or. 335%  by  wt.       Peptones,  present. 
Acid  salts,   2,  or  .007%  by  wt.       Enzymes,  normal. 

Bile,  absent. 
Lactic  acid,  trace.  Mucus,  no  excess. 

Starch,  absent.  Blood,  absent. 

The  K  I  absorption  test  showed  the  presence  of  iodin  in  the 
saliva  in  15  minutes.     The  salol  did  not  react  within  the  hour 


SEASICKNESS  897 

but  reacted  positively  in  1  hour  and  45  minutes.  The  high  per- 
centage of  free  HCl  seems  to  have  been  due  in  part  to  the 
effect  of  the  gastric  extracts. 


The  tests  made  on  subject  "B"  November  20th,  on 
ooard  the  Angler^  were  as  follows:  The  subject  was  de- 
tained unexpectedly  and  had  to  run  650  yards  at  a  good 
pace,  so  as  not  to  miss  the  boat.  After  going  on  board  he 
experienced  some  tightness  in  the  chest  as  if  smoke  were 
in  the  bronchial  tubes,  preventing  the  free  ingress  of  air. 
At  times  he  coughed  like  an  asthmatic.  Undoubtedly 
the  subject's  symptoms  were  due  to  spasm  of  the  bronchial 
muscles.  A  moment  after  entering  the  cabin  the  subject 
began  to  perspire  but  the  tightness  in  the  chest  still  per- 
sisted. At  this  time  the  subject's  anger  was  aroused  by 
the  obstinacy  of  a  disagreeable  individual  who  would  not 
move  his  chair  a  couple  of  inches,  so  as  to  afford  room  for 
the  blood-pressures  to  be  taken  with  comfort  to  all  con- 
cerned. Words  were  exchanged  and  for  a  moment  it 
looked  as  though  the  members  of  the  party  might  have  to 
defend  themselves  against  the  disagreeable  individual  and 
his  friends.  Good  sense  and  sober  judgment  prevailed 
however,  which  was  a  good  thing  for  the  instruments  and 
perhaps  for  a  certain  burly  bully.  The  blood-pressures 
which  were  observed  all  through  the  period  of  possible 
impending  struggle,  i.e.,  from  8. 16  to  8.20  were  155,  150, 
150,  140,  140,  with  corresponding  pulse-rates  of  104,  100, 
104,  100,  100.  At  8. 30  the  subject  felt  well  and  was  perspir- 
ing slightly.  The  blood-pressure  and  pulse-rate  were  180 
and  100  respectively.  At  this  period  the  subject  felt  a 
slight  ache  and  sense  of  fulness  in  the  head.  There  were 
also  some  eructations.  The  boat  was  rocking  slightly,  and 
the  room  was  filled  with  tobacco-smoke.  From  9.12  to 
9.22  the  blood-pressures  were  135,  130,  125,  115,  120,  120, 
115,  120,  115,  and  115,  with  corresponding  pulse-rates 
of  96,  96,  100,  100,  96,  96,  92,  92,  92,  and  96. 

At  9.34  the  blood-pressure  and  pulse-rate  were  115  and 
96  respectively.  At  this  period  the  subject  had  a  slight 
headache,  and  his  face  was  flushed  and  hot.  Air  blew  into 
the  room  fresh  and  cool  from  an  open  door.  At  8.48  the 
boat  was  rolling  and  pitchmg  to  some  extent.  The  subject 
had  a  slight  occipital  headache  on  the  right  side,  extend- 


398  SEASICKNESS 

ing  to  the  ear.  The  face  was  still  flushed  and  warm.  At 
9.58  the  skin  was  moist  from  perspiration,  and  the  subject 
felt  a  little  sick  with  a  slight  "lump-sensation"  in  the 
stomach.  At  10.87  atropin  sulphate,  gr  1/50,  was  given 
hypodermically.  At  10.55  the  face  was  flushed,  and  the 
head  felt  heavy.  At  1 1  the  boat  was  still  rolling  somewhat. 
The  subject  experienced  fulness  in  the  head,  and  had  a 
tendency  to  sleep.  The  face  was  still  flushed.  From 
11.08  to  11.15  the  blood-pressures  were  120,  125,  125, 
125,  with  corresponding  pulse-rates  of  88,  92,  92,  92.  At 
this  period  the  boat  lay  at  anchor,  and  rolled  with  sick- 
ening effect.  The  subject's  mouth  was  dry  from  the  atro- 
pin. The  rolling  of  the  boat  caused  a  little  distress  in 
the  head.  At  11.40  the  stomach  contents  were  removed. 
The  chyme,  which  amounted  to  ^iif,  contained  much  mu- 
cus, a  few  old  blood-stained  scales  and,  toward  the  end, 
a  very  small  amount  of  gross  fat  with  a  little  fresh  blood. 
After  removal  of  its  contents  the  stomach  was  irrigated. 
At  11.57  the  subject  was  given,  per  os,  extract  of  fundic 
and  intermediate  mucous  membrane  of  each  an  amount 
equivalent  to  ^  of  the  yield  of  4  stomachs.  At  12.05 
p.m.  there  was  a  slight  pain  in  the  right  epigastric 
region.  At  12.28  flatus  was  passed,  and  there  was  pain 
in  the  region  of  the  left  iliac  fossa.  The  subject  felt  well 
except  for  those  pains  low  down  in  the  abdomen.  At 
12.82,  an  Ewald  test  meal  was  given.  The  usual  sour 
taste  which  so  often  follows  the  administration  of  atropin 
was  experienced  as  the  subject  ate  his  test  meal.  At 
12.88  there  was  a  cool  pleasant  sensation  in  the  stomach. 
There  were  no  unpleasant  symptoms  of  any  kind,  but  the 
face  was  slightly  flushed.  At  12.48  there  were  intermit- 
tent sharp  colicky  pains  in  the  lower  abdomen.  From 
12.52  to  12.55  the  blood-pressures  were  125,  180,  180, 
180,  with  corresponding  pulse-rates  of  76,  80,  80,  80. 
At  1.80  the  stomach  contents  were  removed.  Owing  to 
persistent  gagging,  it  was  unusually  hard  to  introduce  the 
stomach-tube.  The  chyme,  which  amounted  to  ?iii,  con- 
tained a  moderate  amount  of  mucus,  and  a  few  old  blood- 
stained scales,  but  no  free  blood.  At  1.50  the  blood- 
pressures  were  185,  185,  180,  185,  with  corresponding 
pulse-rates  of  68,  72,  72,  72.  At  2.05,  the  subject  felt 
well  and  enjoyed  a  hearty  dinner,  which  was  followed  by 


SEASICKNESS  899 

a  large  loose  evacuation  of  the  bowels.  Evidently  the 
atropin  and  perhaps  the  gastric  extracts  stimulated  gastro- 
intestinal motility,  for  the  other  subjects  were  somewhat 
similarly  affected,  especially  subject  "S." 

It  is  noteworthy  that  the  atropin  in  the  dose  given 
had  no  effect  in  releasing  the  heart  from  vagus  control  in 
this  subject  as  in  the  others.  This  fact  has  been  repeat- 
edly observed  in  subject  "B"  in  whom  atropin  in  fair 
dosage  generally  tends  to  slow  the  pulse-rate  if  anything. 

Analysis  of  specimen  taken  Nov.  20th  on  board  the  Angler  from 
subject  "B."  Ingested  at  6  a.m.  2  soft-boiled  eggs  with 
4  oz.  of  butter ;  2  cups  of  weak  tea,  with  milk  and  sugar, 
and  6  oz.  of  bread  with  2  oz.  of  butter.  Withdrawn  at  11.40 
a.m.  Amount  of  chyme,  siif.  Macroscopically  there  was 
a  considerable  amount  of  mucus  with  a  few  old  blood-stained 
scales,  a  trace  of  free  fat  and  a  small  amount  of  fresh 
blood.     Resorcin  test  showed  the  absence  of  free  HCl. 

Tot.  acidity,   44,  or  .160%  by  Maltose,  trace. 

wt.  Albumin,  present. 

Free  HCl,  .  Peptones,  present. 

Comb 'd  HCl,    26,  or  .095%  by  Peptonizing  enzymes  (pepsin), 

wt.  diminished  or  absent. 
Tot.  HCl,  26,  or  .095%  by  wt.  Peptonizing    zymogens    (pep- 
Acid  salts,  .  sinogen),  present. 

Lactic,  trace.  Coagulating  enzymes  (chymo- 

Starch,  absent.  sin),  present. 

Amylodextrin,  absent.  Bile,  absent. 

Erythrodextrin,  absent.  Mucus,  some  excess. 

Achroodextrin,  absent.  Blood,  present. 

Note.  The  old  blood-stained  scales  so  often  alluded  to  repre- 
sent epithelium  and  exudate  from  the  gastric  mucous  membrane. 
Evidently  subject  *'B"  suffered  from  a  mild  grade  of  chronic 
gastritis. 

Analysis  of  specimen  taken  Nov.  20,  1910,  on  board  the  Angler 
from  subject  "B."  Ingested  at  12.32  p.m.  an  Ewald  meal. 
Atropin  sulphate,  gr  1  50,  had  been  given  hypodermatically 
at  10.37  a.m.  and  gastric  extract,  fundic  and  intermediate, 
of  each  an  amount  equivalent  to  J  of  the  yield  of  4  stomachs 
at  11.57  per  os.  Withdrawn  at  1.30  p.m.  Amount  of  chyme, 
Siii.  Macroscopically  there  was  a  moderate  amount  of 
mucus  and  a  few  old  blood-stained  scales.  Resorcin  test 
showed  the  presence  of  free  HCl. 

Tot.  acidity,    58,  or  .211%  by      Comb'd  HCl,    22,  or  .080%  by 

wt.  wt. 

Free  HCl,  36,  or  .131%  by  wt.      Tot.  HCl,  58,  or  .211%  by  wt 


400  SEASICKNESS 

Acid  salts,  none.  Albumin,  absent. 

Lactic  acid,  absent.  Peptones,  present. 

Starch,  absent.  Enzymes,  normal. 

Amylodextrin,  absent.  Bile,  absent. 

Erythrodextrin,  present.  Mucus,  moderate  amount. 

Maltose,  trace.  Blood,  absent. 

The  K  I  absorption  test  showed  the  presence  of  iodin  in  the 
saliva  in  12  minutes.  The  salol  test  reacted  positively  in  1 
hour  and  3  minutes. 

Note.  The  high  percentage  of  free  HCl  shown  in  the  above 
analysis  is  unique  for  this  subject.  In  all  analyses  following 
Ewald  test  meals  given  this  subject,  even  in  the  resting  state 
upon  shore,  free  HCl  was  very  low  or  absent.  It  seems,  there- 
fore, justifiable  to  attribute,  in  part  at  least,  the  enhanced  pro- 
duction of  free  HCl  in  this  and  the  other  cases  of  this  day's 
tests  to  the  effects  of  the  gastric  extracts. 

On  November  24th  another  trip  lasting  about  eight 
hours  was  made  on  the  Angler.  The  same  subjects,  viz., 
"  B, "  "  C, "  and  "  S, "  were  used  as  in  the  preceding  tests. 
The  details  of  the  tests  made  on  subject "  B"  are  as  follows : 
At  5.50  a.  m.  breakfast  was  taken,  consisting  of  several  slices 
of  toast  representing  about  3vi  of  bread,  with  ^ii  of  butter 
and  2  cups  of  tea,  to  which  were  added  milk  and  sugar. 
At  8.02  the  blood-pressure  was  185  and  the  pulse-rate  84. 
At  this  time  the  boat  was  still  at  the  pier,  but  was  rock- 
ing very  much  from  the  wash  of  passing  craft.  The  sub- 
ject had  arisen  early,  and  had  plenty  of  time  to  reach  the 
boat,  so  that  there  was  no  hurry  or  rush  as  on  the  previous 
day.  When  the  blood-pressure  above  recorded  was  taken, 
he  was  sitting  in  his  shirt-sleeves  in  a  cool  atmosphere. 
At  8. 15  the  boat  started.  The  weather  was  fair  and  cool, 
but  the  skies  were  overcast.  The  boat  rolled  and  pitched 
somewhat.  At  8.30  the  subject's  face  was  flushed  and 
hot,  and  there  was  a  sense  of  pressure  across  the  abdomen, 
about  the  level  of  the  umbilicus.  The  cabin  was  filled 
with  tobacco-smoke,  the  air  being  anything  but  fresh. 
At  8.40  the  blood-pressures  were  130,  130,  185,  135,  with 
corresponding  pulse-rates  of  72,  76,  76,  76.  At  8.48  the 
subject  had  slight  headache  with  flushed  face.  At  8.59 
there  was  still  some  slight  headache,  and  a  little  nausea. 
The  odour  of  t^jbacco-smoke  was  distinctly  unpleasant. 
The  gloom  of  the  day  seemed  to  attach  itself  to  everything. 
The  subject  felt  warm.     At  this  period  the  boat  was  roll- 


SEASICKNESS  401 

ing  considerably,  and  the  sound  of  the  engines  reverberated 
through  the  head  in  a  distressing  manner.  At  9. 12  the 
blood-pressures  were  125,  125,  125,  130  with  correspond- 
ing pulse-rates  of  76,  76,  80,  80.  At  this  period  there 
was  dizziness  and  heaviness  in  the  head  with  some  head- 
ache, "lump-sensation"  and  a  distinct  tendency  to  sick- 
ness of  the  stomach.  At  9.29  an  Ewald  test  meal  was 
given.  The  stomach  had  not  been  irrigated  before  this 
meal.  The  boat  at  this  time  was  rolling  considerably, 
and  the  subject  felt  some  headache  and  doloi'  cerebri.  At 
9.34  the  boat  was  still  rolling  somewhat,  and  the  subject 
felt  "sick  in  the  head"  with  pain  in  the  occipital  region, 
and  heaviness  about  the  eyes.  The  sense  of  tension  in 
the  muscles  of  the  abdomen  persisted.  At  9.38  the  boat 
was  rolling  and  pitching  badly.  At  10. 14  the  subject  felt 
heavy,  and  there  was  a  burning  sensation  in  the  stomach 
accompanied  by  eructations.  At  10.30,  the  boat  was  still 
rolling  and  pitching.  The  subject  felt  heavy,  and  slightly 
sick.  There  was  a  distinct  "lump-sensation"  in  the 
stomach.  At  10.29  the  gastric  contents  were  removed  and 
the  stomach  irrigated.  The  chyme  amounted  to  |v  and 
contained  much  mucus  and  a  few  old  blood-stained  scales. 
These  latter  were  much  less  than  after  previous  breakfasts 
in  which  eggs  had  been  taken. 

At  10.46  the  boat  lay  at  anchor,  but  it  rolled  constantly 
with  sickening  effect.  At  11.02  atropin  sulphate,  gr  1/50 
was  given  hypodermically.  At  this  time  the  subject  felt 
somewhat  distressed  from  the  constant  rolling.  At  11.12 
the  subject  received,  yer  os,  pyloric  extract  representing  | 
of  the  yield  of  four  stomachs.  The  bulk  of  the  extract 
was  f^iv.  At  11.30  the  blood-pressures  were  125,  125, 
130,  130,  with  corresponding  pulse-rates  of  76,  76,  72, 
72.  The  boat  was  still  rolling  and  the  subject  had  a  slight 
headache.  The  mouth  was  dry  from  the  atropin.  The 
odour  of  tobacco-smoke  seemed  somewhat  changed,  al- 
though not  as  unpleasant  as  usual.  The  stomach  mani- 
fested no  disagreeable  symptoms.  At  11.40  the  mouth 
was  very  dry  and  the  subject  felt  much  better  and  stronger. 
At  11.53  an  Ewald  meal  was  given.  No  sour  taste  was  ex- 
perienced as  on  previous  occasions  after  atropin.  At  1 1. 57 
strychnin  sulphate,  gr  1/30,  was  given  hypodermically. 
The  subject  felt  well  in  every  way,  and  experienced  a  nice 


402  SEASICKNESS 

cool  sensation  in  the  stomach.  He  noticed,  however,  that 
when  he  attempted  to  walk  he  was  unable  to  balance  very 
well,  although  the  tossing  about  did  not  cause  much  dizzi- 
ness or  distress.  Similar  incoordination  following  the 
use  of  atropin  at  sea  was  frequently  observed  in  "B"  and 
other  subjects.  At  12. 10  the  subject  still  felt  well  in  every 
way.  There  were  some  eructations.  The  knee-jerks  were 
somewhat  active.  From  12. 16  to  12.21  the  blood-pressures 
were  130,  125,  130,  125,  120,  115,  120,  with  corresponding 
pulse-rates  of  88,  88,  88,  92,  92,  88,  92.  The  boat  was 
still  rolling  very  much,  but  the  subject  felt  well  in  every 
way.  There  were  some  eructations,  however.  At  12.48 
the  boat  was  still  rolling  very  much  just  off  Sandy  Hook. 
The  subject's  nose  and  mouth  were  very  dry,  but  otherwise 
he  felt  quite  well.  At  12.53  the  stomach  contents  were 
removed.  The  amount  of  chyme  recovered  was  Iss.  It 
contained  nothing  abnormal  macroscopically.  At  1.10 
the  blood-pressures  were  130,  130,  135,  130  with  corre- 
sponding pulse-rates  of  80,  84,  80,  80.  At  this  time  the 
boat  was  rolling  considerably.  The  air  was  chilly,  but 
the  subject  experienced  no  effect  beyond  diyness  of  the 
mouth  and  nose,  and  a  slight,  not  unpleasant  sense  of 
lightness  in  the  head. 

Analysis  of  specimen  taken  Nov.  24th  on  board  the  Angler  from 
subject  "B."  Ingested  at  9.29  a.m.  an  Ewald  test  meal. 
The  stomach  had  not  been  irrigated  and  the  subject  had 
taken  breakfast  at  5.50  a.m.,  consisting  of  toast,  equivalent 
to  §vi  of  bread  with  2  oz.  of  butter  and  two  cups  of  tea 
with  milk  and  sugar.  Removed  at  10.29.  Amount  of  chyme, 
?v.  Macroscopically  there  was  much  tenacious  mucus  and 
a  few  old  blood-stained  scales.  Resorcin  test  showed  the 
presence  of  free  HCl. 

Tot.  acidity,    42,  or  .153%  by  Amylodextrin,  absent. 

wt.  Erythrodextrin,  trace. 

Free  HCl,  24,  or  .087%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,    14,  or  .051%  by  Maltose,  present. 

wt.  Albumin,  trace. 

Tot.  HCl,  38,  or  .138%  by  wt.  Peptones,  present. 

Acid  salts,  4,  or  .014%  by  wt.  Enzymes,  normal. 

Bile,  absent. 

Lactic  acid,  trace.  Mucus,  excessive  amount. 

Starch,  absent.  Blood,  absent. 

Note.  The  products  of  digestion  left  over  in  the  stomach 
from  the  breakfast  at  5.50,  were  undoubtedly  the  cause  of  the 
fair  gastric  secretion  represented  in  the  analysis  above.    In 


SEASICKNESS  403 

similar  test  meals  tried  at  various  times  upon  the  subject,  on  a 
fasting  stomach  or  after  irrigation  the  tests  always  showed 
diminished  or  absent  free  HCl.  Absorption  and  motility  tests 
not  made. 

Analysis  of  specimen  taken  Nov.  24th  on  board  the  Angler 
from  subject  "B. "  Ingested  at  11.53  a.m.  an  Ewald  meal. 
Atropin  sulphate,  gr  1,50,  had  been  given  hypodermically  at 
11.02  a.m.  and  pyloric  extract  §  of  the  yield  of  4  stomachs, 
per  OS,  at  11. 12.  At  11. 57  strychnin  sulphate,  gr  1/30,  was 
given  hypodermically.  Withdrawn  at  12.53  p.m.  Amount 
of  chyme,  §ss.  Nothing  abnormal  macroscopically.  Re- 
sorcin  test  showed  a  very  feeble  reaction  for  free  HCl. 

Tot.  acidity,    30,  or.  109%  by      Achroodextrin,  present, 
wt.  Maltose,  present. 

Free  HCl,  10,  or  . 036%  by  wt.       Albumin,  trace. 

Comb'd  HCl,    10,  or  .036%  by      Peptones,  absent. 

wt.  Peptonizing  enzymes  (pepsin), 

Tot.  HCl,  20,  or  .072%  by  wt.  absent. 

Acid  salts,  .  Peptonizing    zymogens    (pep- 

sinogen) present. 

Lactic  acid,  absent.  Coagulating  enzymes,  normal. 

Starch,  absent.  Bile,  absent. 

Amylodextrin,  absent.  Mucus,  moderate  amount. 

Erythrodextrin,  trace.  Blood,  absent. 

The  K  I  absorption  test  showed  the  presence  of  iodin  in 
the  saliva  in  11  minutes.  The  salol  test  showed  a  positive  re- 
action in  1  hour  and  42  minutes. 

The  low  percentage  of  free  HCl  may,  perhaps,  have  been 
due  in  part,  to  fatigue  of  the  gastric  glands  following  the 
previous  meal.  Absorption  and  motility  were  evidently  favoured 
by  the  pyloric  extract  as  well  as  by  the  atropin  and  strych- 
nin. Owing  to  the  small  amount  of  chyme  the  quantitative 
analysis  involved  some  difficulty,  but  the  figures  given  are  fairly 
reliable,  especially  when  taken  in  conjunction  with  the  result 
of  the  resorcin  test. 

The  details  of  the  tests  made  November  24th  on  sub- 
ject "C"  were  as  follows:  At  7  a.m.  the  subject  took 
a  cup  of  sweetened  lemonade.  At  8  homatropin  was 
instilled  into  the  right  eye.  At  8.05  on  board  the  Angler, 
which  was  still  beside  the  pier,  the  blood-pressures  were 
145,  140,  140,  with  corresponding  pulse-rates  of  100,  104, 
104.  The  boat  was  much  disturbed  by  the  wash  from 
passing  craft.  At  8. 15  the  boat  started.  At  8. 28  the  sub- 
ject drank  ^viii  of  water.  At  8.38  an  Ewald  meal  was 
given,  but  with  only  ^ii  of  water,  as  the  subject  had  had 
fviii  of  water  at  8.28.  At  8.44  the  blood-pressures  were 
130,  130,   135,  140,  140,  with  corresponding  pulse-rates 


404  SEASICKNESS 

of  96,  96,  96,  96,  and  100.  The  slight  rise  in  the  last  two 
pressures  may  have  been  due  to  a  scolding  given  the  sub- 
ject for  taking  water  without  permission  and  for  failing 
to  report  having  taken  it.  At  8.58  the  retinal  arteries 
were  moderately  constricted,  the  veins  being  somewhat 
larger.  At  this  time  the  subject  felt  a  heaviness  in  the 
head,  due  to  the  rolling  and  pitching  which  had  been  con- 
siderable. At  9.16  the  blood-pressures  were  145,  140, 
140,  with  corresponding  pulse-rates  of  100,  100,  96.  At 
9.38  the  stomach  contents  were  removed.  The  chyme 
amounted  to  §iii,  and  was  of  a  dark  brown  (chocolate) 
colour,  with  about  half  an  ounce  of  gross  fat  floating  on 
the  surface.  This  was  the  result  of  chocolate-vanilla  ice- 
cream taken  at  10  p.m.,  on  the  preceding  evening.  At 
9.57  atropin  sulphate,  gr  1/50,  was  given  hypodermically. 
At  9.58  the  subject  was  feeling  badly,  and  had  a  frontal 
headache.  There  was  no  "lump-sensation"  present.  At 
10  the  blood-pressures  were  140,  140,  140,  140,  with 
corresponding  pulse-rates  of  88,  88,  92,  92.  At  10. 15  the 
subject  received,  j'je?*  os,  extract  of  the  fundic  mucous 
membrane,  equivalent  to  ^  of  the  yield  of  4  stomachs  and 
a  similar  amount  of  pyloric  extract.  The  bulk  of  the  ex- 
tract, in  a  watery  diluent,  was  f$v.  At  10.25  the  retinal 
arteries  were  somewhat  larger  than  they  had  been  in  the 
previous  observation. 

The  veins  were  relatively  somewhat  smaller,  but  were 
still  a  trifle  larger  than  the  arteries.  At  10.50  strychnin 
sulphate,  gr  1/30,  was  given  hypodermically.  At  10.55  an 
Ewald  meal  was  given.  At  10.51  the  knee-jerks  were  ab- 
sent even  with  Jendrassik's  reinforcement.  At  11.05  the 
subject  felt  "bad  in  the  head."  There  was  frontal  head- 
ache, as  if  a  tight  band  were  tied  about  the  head.  The 
stomach  felt  very  well.  There  was  no  "lump-sensation" 
and  no  eructations.  At  this  period  there  was  no  nystag- 
mus. At  11.88  the  blood-pressure  was  145,  and  the  pulse- 
rate  100.  The  knee-jerks  were  still  absent,  even  with 
reinforcement.  At  11.55  the  stomach  contents  were  re- 
moved. The  chyme  was  1v  in  amount  and  was  of  a  yel- 
lowish colour.  There  was  no  evidence  of  gross  blood. 
At  12.10  p.m.  the  knee-jerks  were  still  absent,  even  with 
reinforcement.  At  12.28  the  ])l()od-pressures  were  140, 
145,  145,  145,  with  corresponding  j^ulse-rates  of  84,  92, 


SEASICKNESS  405 

92,  92.  The  boat  at  this  time  was  rolling  considerably. 
At  1.18  the  blood-pressiires  were  140,  145,  145,  145,  with 
corresponding  pulse-rates  of  84,  84,  84,  88.  At  1.30 
there  was  a  sour  taste  in  the  mouth,  due  probably  to  the 
atropin.  About  this  time  it  was  suggested  that  the  party 
retire  to  the  dining-room,  but  the  subject  had  no  desire  for 
food.  At  2. 15  he  ate  a  fairly  large  dinner,  consisting  of 
clam  chowder,  turkey  with  dressing,  a  cup  of  coffee,  plum- 
pudding,  and  mince-pie.  This  dinner  was  taken,  al- 
though the  subject  knew  from  previous  experience,  that 
it  would  sicken  him.  At  8.20  he  was  compelled  to  empty 
the  stomach,  which  he  did  in  his  accustomed  way  by  tick- 
ling the  i)harynx  with  his  forefinger.  At  3.30  the  knee-- 
jerks  were  not  only  present  without  reinforcement,  but 
were  somewhat  exaggerated.  From  3  it  was  evident 
that  the  subject  was  beginning  to  have  one  of  the  typical 
gastric  crises  of  tabetic  origin  of  which  he  was  a  victim. 

Analysis  of  specimen  taken  Nov.  24th  on  board  the  Angler  from 
subject  "C. "  Ingested  at  8.38  a.m.  an  Ewald  meal.  The 
subject  had  taken  one  cup  of  sweetened  lemonade  at  7 
a.m.  Withdrawn  at  9.38.  Amount  of  chyme,  ?iii.  On 
macroscopic  examination  the  chyme  was  found  to  be  dark 
brown  in  colour  with  about  half  an  ounce  of  free  fat  floating 
on  the  surface.  Resorcin  test  showed  the  presence  of  free 
HCl. 

Tot.  acidity,    68,  or  .248%  by  Amylodextrin,  absent. 

wt.  Erythrodextrin,  trace. 

Free  HCl,  44,  or  .160%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,    14,  or  .051%  by  Maltose,  present. 

wt.  Albumin,  absent. 

Tot.  HCl,  58,  or  .211%,  by  wt.  Peptones,  present. 

Acid  salts,  10,  or .  036%  by  wt.  Enzymes,  normal. 

Bile,  absent. 

Lactic  acid,  present.  Mucus,  moderate  amount. 

Starch,  absent.  Blood,  absent. 

Note.  The  stomach  evidently  contained  normal  gastric  juice 
at  the  beginning  of  the  meal,  and  the  products  of  digestion 
acted  as  gastric  secretogogues  since  the  percentage  of  free 
HCl  shown  in  the  analysis  is  very  unusual  for  this  subject  after 
similar  test  meals.  The  marked  stasis  of  food  taken  on  the 
previous  evening  is  noteworthy  as  a  precursor  of  the  gastric 
crisis  which  was  evidently  hurried  on  by  the  atropin  and 
strychnin  and  perhaps  by  the  gastric  extracts  for  which  the 
subject  has  a  positive  dislike.  The  enhanced  secretion  of  free 
HCl  may  have  been  due  to  the  early  mild  irritation  of  the 
medullary  centres  incidental  to  the  approach  of  a  gastric  crisis. 


406  SEASICKNESS 

Analysis  of  specimen  taken  Nov.  24th  on  board  the  Angler  from 
subject  "C."  Ingested  at  10.55  a.m.  an  Ewald  meal. 
Atropin  sulphate,  gr  1  50,  had  been  given  hypodermically 
at  9.57  and  strychnin  sulphate,  gr  1  30,  at  10.50,  also  hypo- 
dermically. The  subject  also  had  received,  per  os,  at  10.15 
fundic  extract  equivalent  to  J  of  the  yield  of  4  stomachs  and 
a  similar  amount  of  pyloric  extract.  The  bulk  of  the  ex- 
tracts with  their  watery  diluent  was  3V.  Withdrawn  at  , 
11.55.  Amount  of  chyme,  svss.  On  macroscopic  examina- 
tion the  chyme  was  of  yellowish  colour  with  no  evidence  of 
blood.  Resorcin  test  showed  a  very  feeble  reaction  for 
free  HCl. 

Tot.  acidity,    26,  or  .095%  by  Maltose,  present. 

wt.  Albumin,  trace. 

Free  HCl,  10,  or.  036%  by  wt.  Peptones,  faint  trace. 

Comb'd  HCl,    12,  or  .044%  by  Peptonizing  enzymes,  absent. 

wt.  Peptonizing  zymogens,  dimin- 
Tot.  HCl,  22,  or  .080%  by  wt.  ished. 

Acid  salts,  4,  or  .014%  by  wt.  Coagulating  enzymes,  absent. 

Lactic  acid,  trace.  Coagulating  zymogens,    pres- 
Starch,  absent.  ent. 

Amylodextrin,  trace.  Bile,  absent. 

Erythrodextrin,  present.  Mucus,  moderate  amount. 

Achroodextrin,  present.  Blood,  absent. 

The  K  I  absorption  test  reacted  in  12  minutes.  The 
salol  motility  test  reacted  in  1  hour  and  5  minutes.      • 

The  inefficiency  of  fundic  and  pyloric  extract  to  induce 
secretion  of  a  normal  gastric  juice  in  spite  of  the  fact  that 
absorption  and  motility  were  enhanced  is  noteworthy. 
The  absence  of  symptoms  referable  to  the  stomach  is  to 
be  attributed  to  the  atropin,  although  this  latter  drug  is 
quite  inefficient  in  combating  the  distress  referred  to  the 
stomach  in  gastric  crises.  The  absence  of  skijiped  beats 
in  the  pulse  during  the  forenoon  and  their  reappearance 
on  the  approach  of  the  gastric  crisis  is  also  noteworthy. 
Whether  the  present  test  made  on  this  particular  subject 
is  a  fair  one  as  to  the  efficiency  of  the  combinations  of 
pyloric  and  fundic  extract  is  an  open  question.  The  failure 
of  gastric  secrf;tion  can  hardly  be  attributed  to  pronounced 
medullary  irritation  from  the  oncoming  gastric  crisis, 
because  in  that  case  we  might  expect  marked  gastric  stasis 
and  failure  of  absorption  from  the  same  cause,  whereas 
the  gastric  motility  and  absorption  were  distinctly  en- 
hanced after  strychnin  and  atropin,  etc.  The  failure  of 
normal  gastric  secretion  miglit  possibly  be  attributed  to 


SEASICKNESS"  407 

fatigue  of  the  gastric  glands,  but  in  a  previous  test  where 
intermediate  extract  was  used,  no  such  fatigue  effects  were 
manifested.  The  fact  that  in  subject  "B"  the  gastric 
secretion  was  deficient,  throws  no  light  on  the  subject, 
since  in  his  case  only  pyloric  extract  was  used. 

In  subject  "S"  to  whom  intermediate  extract  was 
given  the  gastric  juice  secreted  was  normal  or  enhanced 
for  this  subject.  It  remains  therefore  a  question  as  to 
whether  the  failure  of  gastric  secretion  in  the  case  of  "B'^ 
and  "C"  was  due  to  fatigue  or  other  cause,  or  to  the  in- 
efficiency of  fundic  and  pyloric  extracts  to  stimulate  the 
gastric  glands  to  activity.  Pending  further  investigation, 
the  latter  view  seems  the  more  probable. 

The  details  of  the  tests  made  November  24th  upon 
subject  "S"  are  as  follows:  At  8.10  a.m.  on  board  the 
Angler  which,  though  still  at  the  pier,  was  rocking  very 
much  in  the  wash  of  passing  craft,  the  blood-pressures 
were  130,  185,  180,  180,  with  corresponding  pulse-rates 
of  72,  68,  76,  68.  At  8.15  the  boat  started  and  at  8.20 
the  fasting  stomach  was  irrigated.  At  8.29  an  Ewald 
breakfast  was  given.  The  boat  at  this  period  was  rolling 
and  pitching  somewhat.  At  8.48  the  blood-pressures  were 
125,  125,  125,  125,  125,  with  corresponding  pulse-rates  of 
76,  76,  76,  68,  64.  At  9. 20  the  blood-pressures  were  125, 
115,  115,  115,  with  corresponding  pulse-rates  of  68,  64,  68, 
68.  At  9.29  the  stomach  contents  were  removed.  The 
chyme  was  jiii  in  amount,  and  was  thin  in  consistency  and 
of  a  yellowish  colour.  At  9.58  atropin  sulphate,  gr  1/50, 
was  given  hy}3odermically.  At  10  the  subject  felt  very 
well.  At  10.05  the  blood-pressures  were  125,  125,  125, 
125,  with  corresponding  pulse-rates  of  56,  60,  60,  56.  The 
boat  was  still  rolling  a  good  deal.  At  10.08  the  subject 
received, ^;er  os^  "intermediate  extract"  equivalent  to  |  of 
the  yield  of  4  stomachs  and  a  similar  amount  of  fundic 
extract.  The  extracts  with  their  watery  diluent  amounted 
to  f^v.  At  10.45  an  Ewald  meal  was  given,  and  at  10.57 
strychnin  sulphate,  gr  1/80,  was  given  hypodermically.  At 
11.06  the  subject  felt  a  band  sensation  around  the  head. 
At  11.17  there  was  slight  dizziness,  although  the  stomach 
felt  very  well.  There  was  no  nystagmus  visible  to  the 
naked  eye.  At  11.40  the  blood-pressures  were  125,  120, 
120,  115  with  corresponding  pulse-rates  Qf  80,  80,  84,  80. 


408  SEASICKNESS 

The  increased  pulse-rate  was  evidently  the  effect  of  the 
atropin  on  the  cardiac  vagus  terminals.  At  11.45  the 
stomach  contents  were  removed.  The  chyme  amounted  to 
3iiss  and  was  of  a  yellowish  colour  with  little  or  no  mu- 
cus. At  12.10  the  knee-jerks  were  active,  but  resembled 
movements  of  voluntary  extension  rather  than  the  sharp 
response  of  the  normal  knee-jerk.  At  12.80  the  blood- 
pressures  were  105,  110,  110,  with  corresponding  pulse- 
rates  of  64,  68,  68.  Evidently  the  effects  of  the  atropin 
upon  the  cardiac  vagus  terminals  and  upon  the  vaso-motor 
mechanisms  had  worn  off.  At  1.20  the  blood-pressures 
were  105,  105,  110,  105,  105  with  corresponding  pulse- 
rates  of  68,  60,  64,  60,  60.  At  1.24  the  subject  felt  very 
well.     At  1.80  there  was  no  great  desire  to  eat. 

Analysis  of  specimen  taken  Nov.  24th  on  board  the  Angler  from 
subject  "S. "  Ingested  at  8.29  a.m.  an  Ewald  breakfast. 
The  fasting  stomach  had  been  irrigated  at  8.20  a.m.  Re- 
moved at  9.29.  Amount  of  chyme,  siii.  Macroscopically 
the  chyme  was  of  yellowish  colour,  thin  in  consistency  and 
contained  no  excess  of  mucus.  Resorcin  test  showed  the 
presence  of  free  HCl. 

Tot.  acidity,    64,  or  .233%  by  Amylodextrin,  trace. 

wt.  Erythrodextrin,  present. 

Free  HCl,  54,  or  .197%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,    4,  or  .014%  by  Maltose,  present. 

wt.  Albumin,  absent. 

Tot.  HCl,  58,  or  .211%  by  wt.  Peptones,  present. 

Acid  salts,    6,  or  021%  by  wt.  Enzymes,  normal. 

Bile,  absent. 

Lactic  acid,  absent.  Mucus,  no  excess. 

Starch,  absent.  Blood,  absent. 

Absorption  and  motility  tests  not  made. 

Note.  The  free  HCl  content  may  here  be  fairly  attributed  to 
the  activity  of  the  well-rested  gastric  glands. 

Analysis  of  specimen  taken  Nov.  24th  on  board  the  Angler  from 
subject  "S. "  Ingested  at  10.45  a.m.  an  Ewald  meal.  At 
9.53  the  subject  received  hypodermically  atropin  sulphate, 
gr  150.  At  10.08  he  received,  per  os,  fundic  and  interme- 
diate gastric  extract  of  each  an  amount  equivalent  to  J  of 
the  yield  of  4  stomachs.  At  10.57  strychnin  sulphate,  gr 
1  30,  was  given  hypodermically.  Removed  at  11.45.  Amount 
of  chyme  liiss.  Macroscopically  the  chyme  was  yellowish 
in  colour  and  contained  nothing  abnormal  Resorcin  test 
phowed  the  presence  of  free  HCl, 


SEASICKNESS  409 

Tot.  acidity,    56,  or  .204%  by  Amylodextrin,  trace. 

wt.  Erythrodextrin,  present. 

Free  HCl,  40,  or  .  146%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,    14,  or  .051%  by  Maltose,  present. 

wt.  Albumin,  absent. 

Tot.  HCl,  54,  or  .197%  by  wt.  Peptones,  present. 

Acid  salts,  2,  or  .007%  by  wt.  Enzymes,  normal. 

Bile,  absent. 

Lactic  acid,  absent.  Mucus,  no  excess. 

Starch,  absent.  Blood,  absent. 

The  K  I  absorption  test  reacted  in  18  minutes.  The  salol 
test  reacted  in  1  hour  and  20  minutes.  The  fairly  normal  gas- 
tric juice  of  the  above  analysis  may  fairly  be  attributed  in 
part,  at  least,  to  the  effects  of  the  gastric  extracts,  as  the 
percentage  of  free  HCl  is  higher  than  that  obtained  in  simi- 
lar test  meals  in  the  resting  condition  on  shore.  It  was  again 
observed  that  in  subjects  "B"  and  "S"  the  bowels  moved 
rather  freely,  on  the  same  afternoon  in  the  case  of  "S, "  and 
on  the  next  morning  in  the  case  of  "B. "  The  latter  subject 
has  a  tendency  to  constipation.  Subject  "C's"  bowels  did  not 
move  that  evening  or  the  next  day,  but  he  received  morphin 
sulphate,  gr  ss. ,  hypodermically  about  5  p.m.  as  he  had  devel- 
oped one  of  his  usual  attacks  of  true  gastric  crises. 

On  January  8th  the  effect  of  hypnotic  suggestion  was 
studied  in  subject  "F."  At  7  a.m.  the  subject  drank 
^iv  of  water.  At  8.07,  on  board  the  Angler^  the  ear 
drums  were  normal,  there  being  no  blood-vessels  visible. 
At  8. 15  the  blood-pressures  were  125,  125,  and  125  with 
corresponding  pulse-rates  of  92,  92,  and  88.  At  8.20  the 
boat  started.  On  ophthalmoscopic  examination  under 
homatropin,  the  retinal  arteries  were  moderately  dilated 
the  veins  being  somewhat  larger.  The  fundus  jerked  to- 
ward the  left  about  every  three  seconds,  at  times  executing 
this  movement  toward  the  left  in  one  sharp  movement,  and 
at  other  times  in  a  series  of  small  jerks.  Later,  the  nystag- 
mic movements  of  the  fundus  toward  the  left  (of  the 
patient)  were  almost  constant.  During  these  observations 
the  subject  sat  erect,  the  coronal  plane  of  his  body  being 
parallel  to  the  long  axis  of  the  boat,  and  his  right  side 
directed  toward  the  bow.  At  this  time  the  boat  was 
rolling  moderately. 

At  8.51  the  blood-pressures  were  130,  135,  135,  and  the 
corresponding  pulse-rates  80,  84,  and  84.  At  9.09  an 
Ewald  meal  was  given.  At  9. 12  the  blood-pressures  were 
185  and  185,  the  pulse-rates  being  76  ^nd  76.     At  this 


410  SEASICKNESS 

time  there  was  slight  horizontal  nystagmus  of  the  fundus 
toward  the  subject's  left.  The  retinal  arteries  were  slightly 
constricted.  Both  arteries  and  veins  seemed  smaller  than 
at  the  previous  examination.  At  times  it  was  difficult  to 
see  the  fundus  properly.  The  boat  continued  to  roll  some- 
what. 

At  9.25  no  vessels  were  visible  in  the  ear  drums.  The 
subject  felt  well  in  every  way.  At  9.42  the  blood-press- 
ures were  185,  180,  185,  the  pulse-rates  being  80,  84  and 
80.  At  10.09  the  retinal  arteries  were  somewhat  con- 
stricted, the  veins  appearing  large,  dark  and  full.  Occa- 
sionally there  were  nystagmic  jerks  of  the  fundus  toward 
the  subject's  left.  At  10.12  the  stomach  contents  were 
removed,  and  the  stomach  irrigated.  The  amount  of 
chyme  recovered  was  fiv.  For  the  purpose  of  removing 
the  stomach  contents,  the  subject  was  hypnotized,  as  his 
pharynx  could  not  tolerate  the  stomach-tube.  On  previous 
occasions  this  subject,  even  under  hypnosis  and  with  ap- 
propriate suggestions,  could  not  tolerate  the  stomach-tube. 
On  this  occasion,  however,  it  was  suggested  to  him,  both 
before  and  during  hypnosis,  that  the  operation  would  cause 
no  discomfort  and  little  difficulty  was  experienced  in  evac- 
uating and  irrigating  the  stomach.  When  the  stomach 
irrigation  had  been  completed,  the  subject  was  allowed  to 
remain  in  hypnosis,  and  at  10.80  an  Ewald  meal  was  given 
with  the  suggestion  that  it  was  cake  and  champagne. 
During  the  meal,  and  at  frequent  intervals  afterward,  it 
was  suggested  that  the  motions  of  the  boat  would  not  cause 
seasickness  or  the  usual  disagreeable  phenomena.  At 
10.51  the  boat  was  rolling  considerably,  and  there  was 
marked  nystagmus  of  the  fundus  to  the  left.  To  the  naked 
eye  at  this  time  there  was  nystagmus  to  the  left,  when  the 
subject  turned  his  eyes  to  the  left,  and  to  the  right  when 
he  turned  his  eyes  to  the  right.  In  an  observation  made 
on  a  subsequent  occasion  on  shore,  it  was  found  that  when 
the  subject  turned  his  eyes  to  the  left  the  latter  jerked 
slightly  with  the  watch,  whilst  with  the  eyes  turned  to  the 
riglit  the  eyes  jerked  tx)  the  right  and  with  the  watch. 
At  11.08  the  retinal  arteries  were  moderately  dilated,  the 
veins  being  full  and  dark.  There  was  slight  nystagmus 
of  the  fundus  to  the  subject's  left,  but  at  times  the  oscilla- 
tions were  simply  back  and  forth  movements  of  about 


SEASICKNESS  411 

equal  rate  and  range.  At  this  time  the  boat  was  rolling 
eo  much  that  subject  "B"  felt  rather  dizzy  and  heavy  in 
the  head.  At  11.22  the  retinal  arteries  were  constricted, 
the  veins  being  dark  and  full.  There  was  horizontal  nys- 
tagmus of  the  fundus  to  the  left.  The  boat,  lying  at  an- 
chor, was  rolling  with  sickening  effect.  At  11.85  the 
stomach  was  evacuated  and  irrigated.  The  amount  of 
chyme  recovered  was  fivss.  At  1.05  p.m.  the  retinal 
arteries  were  constricted.  The  retina  looked  pale,  and 
there  was  nystagmus  of  the  fundus  to  the  subject's 
left.  At  this  time  the  subject  felt  very  dizzy.  In  fact  he 
was  dizzier  and  sicker  under  hypnosis  than  in  the  ordinary 
waking  state.  After  irrigation  of  his  stomach  he  slept 
considerably  and  could  not  be  kept  from  lying  down.  At 
1.09  the  blood-pressures  were  125,  125,  the  pulse-rates  be- 
ing 68  and  68.  The  boat  still  continued  to  rock,  and  the 
subject  felt  dizzy  and  heavy.  At  1.25  there  was  experi- 
enced heaviness  in  the  left  side  of  the  head,  and  the  sub- 
ject felt  hungry,  sleepy,  and  tired.  No  vessels  were  visi- 
ble in  the  membrana  tympani.  At  2  the  subject,  on 
being  taken  out  of  hypnosis,  complained  of  hunger,  but 
on  being  taken  to  the  dining-room,  a  surprisingly  small 
amount  of  food  soon  satisfied  his  appetite. 

During  hypnosis,  on  attempting  to  walk,  the  subject 
almost  fell  down  the  companion-way.  It  seemed  that  his 
powers  of  equilibration  had  become  considerably  disor- 
dered. 


Analysis  of  specimen  taken  from  subject  "F, "  Jan.  8th,  on  board 
the  Angler.  Ingested  at  9.09  a.m.  an  Ewald  breakfast. 
Removed  at  10.12.  Amount  of  chyme,  jivss.  Macroscopi- 
cally  the  chyme  was  normal  in  appearance.  Reaction  (lit- 
mus) acid.     Resorcin  test  showed  the  presence  of  free  HCl. 

Tot.  acidity,    94,  or  .343%  by  Amylodextrin,  present. 

wt.  Erythrodextrin,  present. 

Free  HCI,  80,  or  .292%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,    12,  or  .043%,  by  Maltose,  present. 

wt.  Albumin,  absent. 

Tot.  HCl,  92,  or  .335%  by  wt.  Peptones,  present. 

Acid  salts,  2,  or  .007%  by  wt.  Enzymes,  normal. 

Bile,  absent. 

Lactic  acid,  trace.  Mucus,  moderate  amount. 

Starch,  absent.  Blood,  absent. 

Absorption  and  motility  tests  not  made. 


41^  SEASICKNESS 

Analysis  of  specimen  taken  from  subject  "F,**  Jan,  8th,  on 
board  the  Angler.  Ingested  at  10.30  a.m.  an  Ewald  meal. 
Removed  at  11.35.  Amount  of  chyme,  sivss.  Macroscopi- 
cally  the  chyme  was  normal  in  appearance.  During  the 
period  that  the  meal  was  retained,  the  subject  was  in  wak- 
ing hypnosis  and  under  the  suggestion  that  the  movements 
of  the  boat  would  not  cause  seasickness  or  the  usual  diges- 
tive disturbances.  Reaction  (litmus),  acid.  Resorcin  test 
showed  the  presence  of  free  HCl. 

Tot.  acidity,    66,  or  .240%  by  Amylodextrin,  present. 

wt.  Erythrodextrin,  present. 

Free  HCl,  48,  or  .175%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,    16,  or  .058%,  by  Maltose,  present. 

wt.  Albumin,    faint  trace. 

Tot.  HCl,  64,  or  .233%,  by  wt.  Peptones,  present. 

Acid  salts,  2,  or  .007%  by  wt.  Enzymes,  normal. 

Bile,  absent. 

Lactic  acid,  absent.  Mucus,  moderate  amount. 

Starch,  absent.  Blood,  absent. 

The  K  I  absorption  test  reacted  in  12  minutes.     The  salol 
motility  test  did  not  react  within  the  hour. 

The  details  of  the  tests  made  on  subject  "S"  aboard 
the  Angler^  January  8th,  were  as  follows:  At  6  a.m.  the 
subject  had  breakfast,  consisting  of  bread  and  butter,  with 
milk  and  coffee,  "half  and  half,"  sweetened  with  sugar. 
At  8.08  a.m.  the  ear  drums  were  normal,  no  blood-vessels 
being  visible.  The  blood-pressures  were  130  and  130,  the 
pulse-rates  being  76  and  76.  At  8.20  the  boat  started. 
At  9  the  stomach-tuVje  was  introduced,  but  nothing  was 
recovered.  At  9.38  an  Ewald  meal  was  given.  At  10.38 
the  stomach  contents  were  removed,  and  the  stomach  irri- 
gated. The  amount  of  chyme  recovered  was  ?iii.  During 
the  period  that  the  meal  was  retained,  the  boat  rolled 
moderately.  At  10.48  the  blood-pressures  were  130,  130, 
the  pulse-rates  being  08  and  72.  At  this  time  the  boat 
was  rolling  considerably,  but  the  naked  eye  could  discover 
no  trace  of  nystagmus.  At  10.55  the  boat  was  still  rolling 
))adly,  and  when  the  subject  turned  his  eyes  to  the  right 
or  hift,  a  trace  of  horizontal  nystagmus  was  visible.  At 
11.07  the  blood-pressures  were  125,  125,  the  pulse-rate 
being  68  and  72.  At  this  time  the  boat  was  rolling  and 
pitching  considerably.  At  11.08  the  subject  was  given, 
per  OS,  pyloric  extract  equivalent  to  the  yield  of  1\  stom- 
achs.    This  extract  had  been  made  on  January  5th.     At 


SEASICKNESS  413 

11.52  the  blood-pressures  were  125,  125,  125,  the  pulse- 
rates  being  64,  64  and  64.  At  this  time  the  boat  was 
lying  at  anchor,  but  rolling  considerably.  At  11.57  an 
Ewald  meal  was  given.  At  12.08  p.m.  the  boat,  still  at 
anchor,  was  rolling  badly.  The  blood-pressures  were  120, 
115,  125,  130,  the  pulse-rates  being  64,  64,  68  and  64. 
About  this  time  the  subject  complained  of  cramps  in  the 
stomach,  caused  probably  by  the  pyloric  extract.  At 
12.57  the  stomach  contents  were  removed  and  the  stom- 
ach irrigated.  The  amount  of  chyme  recovered  was  3iiiss. 
At  1.23,  the  blood-pressures  were  120,  115,  the  pulse-rates 
being  68  and  68.  The  patient  was  but  little  affected  by 
the  motions  of  the  boat  during  the  trip,  and  felt  fairly 
well.  At  1.25,  on  looking  to  the  right  or  left,  a  trace  of 
horizontal  nystagmus  was  visible.  There  was  no  vertigo 
or  sense  of  dizziness 

Analysis  of  specimen  taken  from  subject  "S,"  J^n.  8th,  on  board 
the  Angler.  Ingested  at  9. 38  a.  m.  an  Ewald  meal.  Removed 
at  10.38.  Amount  of  chyme,  liii.  Macroscopically  the 
chyme  was  normal  in  appearance.  Reaction  (litmus),  acid. 
Resorcin  test  showed  the  presence  of  free  HCl. 

Tot.  acidity,    56,  or  .204%  by  Amylodextrin,  absent. 

wt.  Erythrodextrin,  present. 

Free  HCl,    34,  or .  124%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,    16,  or  .058%  by  Maltose,  present. 

wt.  Albumin,    faint  trace. 

Tot.  HCl.,  50,  or.  182%  by  wt.  Peptones,  present. 

Acid  salts,  6,  or  .021%  by  wt.  Enzymes,  normal. 

Bile,  absent. 

Lactic  acid,  absent.  Mucus,  moderate  amount. 

Starch,  absent.  Blood,  absent. 

Absorption  and  motility  tests  not  made. 

Analysis  of  specimen  taken  from  subject  **S, "  Jan.  8th,  on  board 
the  Angler.  Ingested  at  11.57  a.m.  an  Ewald  meal.  Re- 
moved at  12.57  p.m.  Amount  of  chyme,  ?iiiss.  Macroscopi- 
cally the  chyme  was  normal  in  appearance.  At  11.08  the 
subject  had  received,  per  os,  pyloric  extract  equivalent  to 
the  yield  of  li  stomachs.  Reaction  (litmus),  acid.  Resor- 
cin test  showed  the  presence  of  free  HCl. 

Tot.  acidity,    66,  or  .240%  by  Tot.  HCl,  64,  or  .232%  by  wt 

wt.  Acid  salts,  2,  or  .007%  by  wt. 

Free  HCl,  50,  or  .182%  by  wt. 

Comb'd  HCl,    14,  or  .051%  by  Lactic  acid,  absent. 

wt.  Starch,  absent. 


414  SEASICKNESS 


Amylodextrin,  present.  Peptones,  present. 

Erythrodextrin,  present.  Enzymes,  normal. 

Achroodextrin,  present.  Bile,  present. 

Maltose,  present.  Mucus,  moderate  amount. 

Albumin,   faint  trace.  Blood,  absent. 

Absorption  and  motility  test  not  made. 


The  details  of  the  tests  made  on  subject  "B"  aboard 
the  Angler,  January  8th,  were  as  follows:  At  4.45  a.m., 
the  subject  drank  3viii  of  water.  At  6.15  he  had  break- 
fast, consisting  of  bread  5viii,  butter  jiv,  and  tea  fxiv 
with  milk  and  sugar.  At  8.11  the  blood-pressures  were 
185,  135,  the  pulse-rates  being  lOO  and  104.  At  8.20  the 
boat  started.  At  this  time  the  boat  was  rolling  consider- 
ably, so  that  the  subject  felt  a  little  dizziness  and  heavi- 
ness in  the  head.  At  9.22  the  subject  complained  of  ful- 
ness and  lightness  in  the  head  and  of  a  band  sensation 
about  the  lower  portion  of  the  thorax  (hypochondriac 
region).  At  9.80  the  gastric  contents  were  removed, 
and  the  stomach  irrigated.  The  amount  of  chyme  re- 
covered was  ^viii.  It  contained  much  thick  mucus,  a 
few  old  blood-stained  scales,  and  much  fat.  There  was  a 
distinct  odour  of  lactic  acid.  At  9.58  an  Ewald  meal  was 
given.  At  10.88  the  blood-pressures  were  125,  125,  the 
pulse-rates  being  84  and  84,  At  10,40  pyloric  extract, 
equivalent  to  the  yield  of  \\  stomachs,  was  given  ^er  os. 
At  10.42  the  boat  was  rolling  and  pitching  considerably. 
The  subject  felt  heavy  in  the  head,  and  his  face  was 
flushed  and  hot,  though  the  rest  of  his  body  was  cool.  At 
10.49  the  boat  was  still  rolling,  and  pitching  badly.  The 
subject,  who  was  sitting  upright  with  his  coronal  plane 
parallel  to  the  long  axis  of  the  ])oat,  exhibited  no  signs  of 
nystagmus.  At  10,58  the  blood-pressures  were  115,  115, 
the  pulse-rates  being  84  and  84.  At  11,05  the  boat  was 
still  rolling  and  pitching.  The  subject  complained  of 
heaviness  in  the  head.  The  face  was  flushed  and  hot, 
whilst  the  stf)mach  felt  well .  At  1 1 . 1 2  the  blood-pressures 
were  125,  125,  the  pulse-rates  being  88  and  84.  The  head 
still  felt  a  little  heavy,  but  the  stomach  felt  well.  At 
11.15  an  Ewald  meal  was  given.  At  this  time  the  boat, 
lying  at  anchor,  rolled  considerably  and  with  sickening 
effect.     At  11,80  the  blood-pressures  were  140,  145,  145, 


SEASICKNESS  415 

the  pulse-rates  being  84,  84  and  84.  At  this  time  the 
boat  lay  very  still  at  anchor,  and  the  subject  felt  very 
well.  At  11.47  the  boat,  still  at  anchor,  rolled  consider- 
ably. The  subject  felt  a  sensation  of  warmth  in  the  stom- 
ach. There  were  some  eructations.  At  11.57  the  blood- 
pressures  were  130,  180,  the  pulse-rates  being  80  and  80. 
At  12.11  p.m.  the  boat  was  rocking  considerably,  and 
the  subject's  head  felt  heavy.  At  12.14  the  boat  was 
steady.  At  12. 15  the  gastric  contents  were  removed,  and 
the  stomach  irrigated.  The  amount  of  chyme  recovered 
was  fiii.  It  contained  much  mucus.  At  12.41  the  sub- 
ject complained  of  pains  in  the  lower  abdomen.  At  12.50 
the  blood-pressures  were  115,  115,  the  pulse-rates  being 
80  and  80.  At  this  time  the  boat  was  still  at  anchor  and 
rolling  considerably.  At  1.18  the  blood-pressures  were 
120,  115,  the  pulse-rates  being  80  and  80.  The  boat  was 
rolling  slightly  at  this  time,  and  the  subject  had  a  burn- 
ing sensation  referred  to  the  epigastrium,  and  a  slight 
ache  in  the  top  of  the  head,  with  a  sense  of  fulness  in  the 
latter.  At  1.25  on  turning  the  eyes  to  the  left,  there  was 
slight  horizontal  nystagmus  to  the  left.  On  looking  to 
the  right  there  was  no  visible  nystagmus. 


Analysis  of  specimen  taken  from  subject  "B,"  Jan.  8th,  on  board 
the  Angler.  Ingested  at  6. 15  a.  m.  breakfast  consisting  of 
bread  Iviii,  butter  ^iv,  tea  Ixiv,  with  milk  and  sugar. 
Removed  at  9.30.  Amount  of  chyme,  oviii.  The  chyme 
contained  much  thick  mucus,  a  few  old  blood-stained  scales, 
and  a  quantity  of  fat.  There  was  a  distinct  odour  of  lactic 
acid.  Reaction  (litmus),  acid.  Resorcin  test  showed  a  fee- 
ble reaction  for  free  HCl. 

Tot.  acidity,    38,  or  .138%  by  Maltose,  trace. 

wt.  Albumin,  trace. 

Free  HCl,  18,  or  . 065%  by  wt.  Peptones,  present. 

Comb'd  HCl,    18,  or  .065%  by  Peptonizing  enzymes,    dimin- 

wt.  ished. 

Tot.  HCl,  36,  or  .  130%  by  wt.  Peptonizing    zymogens,     nor- 
Acid  salts,  2,  or  .007%  by  wt.  mal. 

Lactic  acid,  present.  Coagulating  enzymes,  normal. 

Starch,  absent.  Bile,  absent. 

Amylodextrin,  absent.  Mucus,  in  excess. 

Erythrodextrin,  absent.  Blood,  trace. 

Absorption  and  motility  tests  not  made. 


416  SEASICKNESS 

Analysis  of  specimen  taken  from  subject  "B,"  Jan.  8th,  aboard 
the  Angler.  Ingested  at  11.15  a.m.  an  Ewald  meal.  Re- 
moved at  12.15.  Amount  of  chyme,  ?iii.  The  chyme  con- 
tained a  considerable  amount  of  thick  mucus  and  a  few 
blood-stained  flakes.  At  9.58  an  Ewald  meal  had  been 
taken  and  retained  permanently.  At  10.40  pyloric  extract, 
equivalent  to  the  yield  of  li  stomachs,  had  been  taken  per  os. 
Reaction  (litmus),  acid.  Resorcin  test  showed  the  presence 
of  free  HCl. 

Tot  acidity,    44,  or  .160%  by  Amylodextrin,  present. 

wt.  Erythrodextrin,  present. 

Free  HCl,  22,  or  . 080%  by  wt.  Achroodextrin,  present. 

Comb'd  HCl,    20,  or  .073%  by  Maltose,   present. 

wt.  Albumin,  trace. 

Tot.  HCl,  42,  or  .153%  by  wt.  Peptones,  present. 

Acid  salts,  2,  or  .007%  by  wt.  Enzymes,  normal. 

Bile,  absent. 

Lactic  acid,  absent.  Mucus,  in  excess. 

Starch,  absent.  Blood,  trace. 

Absorption  and  motility  tests  not  made. 

The  urine  after  the  tests  had  a  specific  gravity  of  1018  and 
did  not  react  for  albumin,  sugar,  glycuronic  acid  or  phosphates. 


CHAPTER  XXIX 

GENERAL    CONCLUSIONS   FROM    STUDIES    IN   SEA- 
SICKNESS.   PROTOCOLS 

The  general  conclusions  from  the  foregoing  observa- 
tions are  as  follows : 

1.  The  effects  of  seasickness  upon  the  organism  as  a 
whole,  and  upon  the  mechanisms  of  the  circulation  and 
digestion  are  quite  analogous  to  those  of  the  sickness 
caused  by  rotation,  aural  irrigations,  and  by  galvanism 
applied  over  the  mastoid  areas. 

2.  Disturbances  of  the  circulation  are  not  the  primary 
cause  of  seasickness  since  the  chief  subjective  phenomena 
of  the  malady  are  found  present,  simultaneously  with 
both  efficient  and  impaired  states  of  the  circulatory 
mechanisms.  Disturbed  circulation,  however,  especially 
vaso-motor  exhaustion,  is  frequently  associated  with  sea- 
sickness and  is  an  important  feature  of  the  malady. 

3.  Digestive  disturbances,  similarly,  are  not  the  pri- 
mary cause  of  seasickness,  though  they  are  constant  accom- 
paniments and  frequently  the  most  salient  and  distress- 
ing features  of  the  condition.  The  firm  and  persistent 
closure  of  the  pylorus  and  the  lowered  acidity,  as  seen  in 
the  analyses  of  the  gastric  contents,  are  identical  with  the 
phenomena  observed  in  rotations  and  aural  irrigations. 
In  extreme  conditions,  such  as  those  encountered  on  the 
Lady  Wolseley  and  on  the  Quatre  Freres,  there  was  com- 
plete absence  of  acids  and  digestive  enzymes.  Prolonged 
exposure  to  conditions  that  cause  seasickness  are  undoubt- 
edly injurious  to  the  digestive  organs,  and  more  especially 
to  the  stomach  which  may  become  seriously  impaired  in 
its  functions  and  even  the  seat  of  organic  disease.  Thus 
subject  "B"  undoubtedly  developed  during  the  various 
journeyings  a  mild  grade  of  chronic  gastritis.     The  irregu- 

417 


418  SEASICKNESS 

lar  mode  of  life  and  the  alcohol  taken  by  him  during  the 
period  extending  from  July  10th  to  July  27th,  were  prob- 
ably factors  in  the  causation  of  his  gastritis,  but  the  con- 
tinually repeated  perturbations  of  the  nervous  mechanisms 
controlling  the  general  circulation  as  well  as  gastric  secre- 
tion and  motility  were  the  chief  cause. 

4.  Disordered  states  of  the  circulatory  and  digestive 
mechanisms  when  once  initiated  become  powerful  second- 
ary sources  of  irritation.  Thus  injudicious  muscular  ex- 
ertion, the  retention  of  stagnant  gastric  contents  or  the 
introduction  of  improper  food  into  the  rebellious  and 
highly  irritable  stomach  tend  greatly  to  over-irritation  and 
exhaustion  of  the  gastric  vagal,  vaso-constrictor  and  other 
centres. 

5.  The  ventilation  and  temperature  of  the  cabin  are 
also  important  secondary  factors  in  seasickness,  the  cool, 
well-ventilated  room  tending  greatly  to  restore  the  individ- 
ual, whilst  a  hot  stuffy  cabin  may  cause  disturbances  of 
the  circulatory  and  digestive  mechanisms  as  distressing 
almost  as  those  which  occur  in  seasickness  though  caused 
primarily  in  another  way. 

6.  Cold  bathing  and  the  employment  of  methods  or 
drugs  calculated  to  enhance  directly  vaso-motor  efficiency 
by  stimulation  of  the  nervous  centres  are  contraindicated 
where  the  circulatory  depression  is  due  to  exhaustion 
from  over- irritation.  Muscular  exertion  in  these  condi- 
tions is  therefore  injurious.  At  a  later  stage,  when  there 
is  evidence  of  restoration  of  function  on  the  part  of  the 
nervous  centres,  and  when  there  is  reason  to  believe  the 
stage  of  exhaustion  is  past,  mild  exercise,  massage  and 
hydrotherapy  are  of  undoubted  benefit.  The  last  of  these 
measures,  however,  has  to  be  resorted  to  with  the  greatest 
caution  and  only  after  special  study  of  the  peculiarities 
of  the  individual's  circulatory  mechanisms.  For  even 
more  imperative  reasons  drugs  and  procedures  that  tend 
to  depress  or  over-stimulate  the  vaso-motor  mechanisms, 
or  indeed  any  of  the  medullary  centres,  are  contraindi- 
cated. Drugs  that  depress  the  psychic  and  higher  centres, 
such  as  bromides  and  alcohol,  are  on  the  whole  of  ques- 
tionable benefit  and  alcohol  in  excessive  quantities  is 
distinctly  harmful  to  the  circulation.  The  effects  of  mor- 
phin,    cocain,    hyoscin,    and   nitroglycerin    in    rotation 


SEASICKNESS  419 

sickness  were  such  as  to  offer  little  hope  of  usefulness  in 
seasickness.  They  were,  therefore,  excluded  from  the  list 
of  possible  safe  and  beneficial  measures. 

7.  Psychic  depression,  and  disagreeable  sights  and 
odours  are  also  important  secondary  causes  of  distress. 
Hence  sunshine  and  clear  weather  with  pleasant  surround- 
ings and  agreeable  companionship  are  of  benefit. 

8.  Since  exhaustion  of  the  nervous  centres  is  charac- 
teristic of  seasickness  at  its  height,  mental  effort,  especial- 
ly when  coupled  with  the  use  of  the  eyes  as  in  reading, 
may  be  particularly  harmful.  Quite  frequently  during 
the  progress  of  recovery  from  an  acute  spell  of  seasickness 
subject  "B"  has  retarded  his  recovery  by  thinking  too 
intently  over  his  future  plans  or  by  emotional  reading 
or  by  indulging  in  a  train  of  emotional  thought. 

9.  Recovery  from  seasickness  means  the  adaptation  of 
the  individual's  organism  to  the  rhythm  and  extent  of  the 
movements  of  that  particular  boat  upon  which  he  has  been 
travelling.  Hence  a  traveller  may  have  recovered  from 
seasickness  upon  an  ocean  liner  and  later  fall  a  victim  to 
the  motions  of  a  Channel  steamer.  Even  marked  aggra- 
vation of  the  movements  of  the  boat  upon  which  an  indi- 
vidual has  recovered  may  cause  a  return  of  all  the  phe- 
nomena of  seasickness.  This  frequently  occurs  under 
varying  conditions  of  weather. 

Frequently  individuals  who  were  for  the  greater  part 
of  their  lives  victims  of  seasickness  lose  their  suscepti- 
bility. On  the  other  hand  persons  who  have  been  im- 
mune may,  at  some  time  or  other,  develop  a  susceptibility 
for  the  malady.  This  is  one  of  the  mysteries  which 
sailors  and  others  hurl  at  the  medical  man  who  presumes 
to  know  anything  about  seasickness.  However,  bilateral 
degeneration  of  the  eighth  nerve  which  so  frequently  oc- 
curs in  advancing  years  and  earlier  in  certain  families, 
accounts  for  the  first  class  of  cases.  If  the  degeneration 
progresses  irregularly  so  that  the  nerve  on  one  side  alone 
is  affected  or  is  affected  to  a  greater  or  less  extent  than 
the  nerve  on  the  other  side,  we  have  a  condition  of  rela- 
tive heightened  irritability  of  the  vestibular  nerve  endings 
in  one  labyrinth  which,  as  we  have  seen  under  aural  irriga- 
tions, is  the  great  cause  of  disturbance  of  the  vestibulo- 
cerebellar mechanisms  involved  in  equilibration.     Actual 


/ 


420  SEASICKNESS 

cases  of  this  kind  have  been  studied,  but  the  details  will 
be  related  in  another  chapter. 

10.  Atropin,  more  especially  in  combination  with 
strychnin,  is  effective  in  combating  the  subjective  symp- 
toms of  seasickness,  especially  the  nausea  and  the  gastric 
and  cerebral  discomfort,  but  it  has  no  direct  effect  in  pro- 
moting gastric  secretion  and  digestion,  and  does  not  pre- 
vent the  incoordination  or  disturbances  of  equilibrium  in- 
cidental to  seasickness  although  it  tends  to  eliminate  the 
associated  sense  of  vertigo. 

11.  Although  the  tests  made  on  January  8th  afford,  in 
themselves,  no  satisfactory  basis  for  conclusions  as  to  the 
effect  of  hypnotic  suggestion  in  seasickness,  the  results 
obtained,  especially  when  taken  into  consideration  with 
the  results  obtained  from  hypnotic  suggestion  in  aural 
irrigations  and  rotations,  indicate  that  hypnotic  sugges- 
tion is  not  a  very  efficient  means  of  offsetting  or  prevent- 
ing the  effects  of  seasickness  even  during  actual  hypnosis, 
not  to  mention  the  rapidly  waning  influence  of  post- 
hypnotic suggestion.  It  is  to  be  regretted  that  further 
opportunity  has  not  so  far  presented  itself  for  the  study 
of  this  important  phase  of  the  subject. 

12.  The  fact  that  extracts  made  from  the  various  por- 
tions of  the  gastric  mucous  membrane  were  about  equally 
efficient  (in  some  instances  the  "intermediate  extract" 
appearing  to  be  the  most  efficient  of  the  three)  in  stimu- 
lating the  flow  of  normal  gastric  juice  seems  to  indicate 
that  the  effects  of  the  extracts  were  due  to  the  contained 
substances  with  secretogogue  action  rather  than  to  gastric 
secretin  developed  by  decoction.  This  fact  was  more  ap- 
parent in  subsequent  tests  made  on  shore  and  reported  else- 
where. In  these  tests  it  was  found  that  ordinary  broth 
was  as  efficient,  and  at  times  more  so  than  decoctions  of 
pyloric  or  fundic  mucous  membrane.  Following  the  ad- 
ministration of  these  extracts  no  appreciable  alterations 
in  blood-pressure  or  pulse-rate  were  observed  which  could 
be  safely  attributed  to  the  extracts.  It  seems  reasonable, 
therefore,  to  conclude  that  gastric  secretin  is  inert  when 
administered ^er  os  (possibly,  because  of  changes  induced 
as  the  decoction  reaches  the  stomach)  and  that  the  effect 
of  decoctions  of  the  gastric  mucous  membrane  given  ^jer 
OS  in  promoting  the  flow  of  normal  gastric  juice  is  due  to 


SEASICKNESS 


421 


other  substances  (secretogogues)  contained  in  the  decoc- 
tions. In  the  matter  of  enhancing  the  flow  of  gastric 
juice,  therefore,  decoctions  of  gastric  mucous  membrane 
have,  when  administered  j^^^r  os  no  advantage  over  ordi- 
nary meat-extracts,  such  as  beef  tea,  soup,  etc.  Decoc- 
tions of  gastric  mucous  membrane  seem  however  to  aid 
absorption  and  to  promote,  to  some  extent,  gastric  and  in- 
testinal motility. 


STUDIES   IN    SEASICKNESS 


Protocol  1. — Observations  made  on  subject  "B"  aboard  the 
steamship  "Taurus"  Dec.  27,  1908.  Temperature  of  air 
60°  F. 


Time, 
a.ni. 

8:25 

8:37 

8:45 

9:30 

10:00 

10:30 

11:05 

12:30 


Pulse-  Blood- 
rate,     press. 


96 
96 
92 
92 

80 
76 
68 
68 
68 
72 
68 
64 
64 


120 
120 
115 
120 
110 
105 
105 
95 
105 
100 
110 
110 
110 


Remarks. 

On  boat  before  starting. 
<  <  <  <  <  < 

After   start.     Slight   roll.      Weather  calm. 

Slight  headache. 
<  < 

Pulse  slightly  irregular. 
Headache.     Face  flushed. 
Conjunctivae  slightly  congested. 

At  anchor. 


Protocol  2.— On  "B  "  aboard  steamer  "Angler,"  April  4, 1909. 


8:05 
8:10 
8:11 


20 
22 
26 


84 
80 
88 
80 
80 
80 
84 


8 :  28  80 
8 : 29  80 
8 ;  32     88 


105 
110 
115 
125 
125 
120 
120 
125 

125 
120 
125 


On  boat  after  slight  injury  of  hand. 
Feels  well  in  fresh,  cool  air. 
Boat  started. 


Conjunctivae  slightly  congested. 

Feels  well.     Draught  on  right  shoulder. 

Dizzy ;    slight   lump-sensation ;    fulness    in 

head. 

Well  again,  but  some  fulness  in  head  still. 
<<  <<  <<  <<  << 

Feels  well,  but  has  fulness  in  head  and  is 

slightly  dizzy. 


422  SEASICKNESS 


Remarks. 

Taking  deep  breaths.  Conscious  of  heart 
action  after  slight  exertion,  viz. :  standing 
on  seat. 

Frontal  headache.  Fulness  in  head.  Con- 
junctivae congested. 

Face  pale.    Slight  nausea ;  stomach  distress. 

Draught  on  shoulder.  Feels  as  if  about  to 
sneeze. 

Dizzy  and  mentally  depressed. 

<  <  <  <  <  < 

Feels  well.     Sight  of  water  rushing  by  dis- 
tresses. 
Cold  on  one  side  because  of  draughts. 
Face  pale.    Conjunctivae  congested.     Pupils 

normal. 
Face    pale.      Cheeks    warm.      Feels   well. 

Eructations. 
Artery  contracted.     Feels  depressed. 
Lump-sensation.    Fulness  in  head.    Eructa- 
tions. 
Nauseated.     Sense  of  fulness  in  ears.     Boat 

steady. 
Conscious  of  respiratory  movements. 
Sense    of    tension    in    scalp  over  occiput. 

"Lump-sensation"  in  stomach. 
Abnormal   sensation  (fulness)  in   left  ear. 
Head   heavy   and   full.     "Lump."     Dizzy. 
Uninterested. 
9 :  06     76      125      Taking  deep  breaths.     Nauseated.     Not  so 

depressed  now. 
9 :  12     76      125      "Lump. "  Sense  of  weight  in  frontal  region. 

Conscious  of  stomach  contractions. 
9:13     72        25      Eructations.     "Lump. "  Nausea. 
9 :  15     76      125      Moving  head  from  side  to  side  aggravates 

nausea. 
9 :  17     72      125      Dizzy  as  boat  lurched. 
9:25     80      120      "Lump."    Dizzy.    Arteries  contracted. 
9 :  41     72      125      Sick  feeling  in  head.    Deep  breaths.     Noise 

of  water  distresses. 
9:46     68      125      Fulness  about  ears  as  if  head  was  in  the 

grip  of  something. 
9:52     68      125      "Lump."    Eructations.     Boat  rolling.     Sa- 
liva increased. 
9 :  55     68      120      Conjunctivae  congested.     Face  not  so  pale 

now.     Yawning. 
9:57     68      120      Boat  rolling  and  pitching.  Dizzy.     Arteries 
contracted.      Deep    breaths.       Yawning. 
Eructations. 
10 :  00     68      120      Tobacco-smoke    inoffensive    to  smell.     Sub- 
ject has  been  out  on  bow. 


Time,  '. 
a.m. 

8:33 

Pulse-  Blood- 
rate,  press. 

76   125 

8:35 

76 
72 

120 
120 

8:37 
8:38 

80 

76 

120 
125 

8:39 
8:40 
8:41 

76 

72 
80 

120 
120 
125 

8:43 
8:44 

72 
76 

120 
120 

8:49 

72 

120 

8:51 
8:56 

76 
72 

125 
125 

8:58 

76 

120 

9:00 
9:01 

76 

72 

125 
125 

9:03 
9:04 

76 
76 

125 
125 

SEASICKNESS  423 

V^^'   ^JiT^}^'  Remarks. 

a.in.      rate,    press. 

10 :  02  68  120  Photophobia.  Sneezed.  Muscular  tremors. 
Dizzy.  Difficulty  in  balancing.  Mental 
effort  causes  distress  in  head. 

10 :  03     68      120      Arteries  contracted  moderately. 

10:11  68  130  Feels  well.  Slight  "lump."  Arteries  con- 
tracted. 

10 :  13     68      135      Arteries  much  contracted. 

10:15     68      125      Feels  well. 

10 :  17  72  125  Arteries  contracted.  Conjunctivae  con- 
gested.    Pupils  normal. 

10 :  20  64  125  Sense  of  weight  in  head.  Boat  rolling  and 
pitching. 

10 :  22  64  130  Arteries  contracted.  Deep  breaths.  Fron- 
tal headache. 

10 :  24     72      125      Lightness  in  head.     Feels  well. 

10 :  37     64      125      Boat  stopped.     Feels  well.     Air  cold. 

10:38  68  135  Tobacco-smoke  not  disagreeable  but  not 
pleasant. 

10 :  42     64      125      At  anchor.     Fulness  in  head. 

10 :  10     64      125      Slight  eructations.     Deep  breaths. 

11:15     64      125 

12 :  00  68  115  Feels  well.  Hands  cold.  Face  flushed  and 
warm. 

12:04    '68      125      Feels  well. 

1 :  40     72      120      Ate  an  orange.    Feels  refreshed.    Boat  roll- 
ing. 
1:43     68      125      Fulness  in  head.     Arteries  moderately  con- 

1:46  68  125  Strolled  on  deck. 

2 :  22  68  120  Feels  well.    Pupils  and  conjunctivas  normal. 

2 :  25  68  125  Artery  moderately  large.  Stomach  and  head 
feel  well. 

2 :  27  68  125  Feels  well  in  every  way. 

2 :  28  64  125  Weighed  anchor.     Boat  rolling  some. 

2 :  30  68  125  Fulness  and  lightness  in  head.  Feels  fairly 
well. 

2 :  47  68  125  Before  starting  homeward  feels  well. 

2 :  49  68  125  Not  yet  started.     Artery  normal. 

2 :  52  72  125  Boat  rolling.     Fulness  in  head. 

2:58  68  125  Artery   contracted   somewhat.     Feels  well. 

3:01  64  125 

3 :  03  68  125 

3 :  04  64  120  Boat  started  homeward.     Eructation. 

3 :  05  64  120  Headache.     Face  flushed.     Feels  well. 

3 :  06  64  120  Fulness  in  head.     Face  hot. 

3 :  09  64  120  Sense  of  weight  in  head.     Feels  well. 

3 :  12  68  120  Sight  of  passing  water  distresses. 

3:30  68  125  Odour  of  tobacco-smoke  slightly  disagree- 
able. 


424  SEASICKNESS 


Protocol   3.— On   "B"  aboard   steamer  "Angler,"  May  30, 

1909. 

Time,    Pulse-  Blood-  Remarks. 

a.m.       rate,  press.  «"«.«. 

7 :  46     80  120      On  boat  resting. 

76  120 

76  120 

76  120 

72  115        " 

76  120 

76  120 

76  115        " 

76  120 

76  120 

76  120 

76  125        " 

76  120 

76  125 

8 :  14     Boat  starts.     Weather  fine.     Boat  steady. 

8:15  72  120 

72  130 

80  125 

76  115 

72  120 

72  120 

8 :  21     Ewald  breakfast 

8:22     76  120 

76  125 

80  120 

76  120 

8:45     76  120      "Lump-sensation."    Saliva  increased. 

72  120      Fulness  in  head.     Eructations. 

76  120 

72  120 

72  120 

72  115 

72  115 

9 :  08     76  110      Dizzy.     Fulness  in  head.     Saliva  increased. 

72  110 

72  110 

72  105 

9:14     72  110      Frontal    headache.      "Lump-sensation"    in 
stomach. 

72  110 

72  110 

72  105 

9 :  19     76  110      General  headache.     Fulness  in  top  of  head. 

72  105 

68  115 

76  115 

76  HO      Ache  over  eyes.     Pain  in  eyeballs. 


SEASICKNESS  425 


Time, 

Pulse-  Blood- 

Remarks. 

a.m. 

rate. 

press. 

76 

115 

"Lump-sensation. " 

72 

115 

9:32 

76 

115 

Boat  rolling  some.    Headache.    Eructations. 

72 

115 

9:35 

76 

115 

Eructations.     Disinclined  for  work. 

72 

110 

68 

110 

68 

110 

9:53 

68 

115 

Frontal  headache. 

9:55 

72 

110 

Dizzy.     Lump-sensation. 

76 

115 

72 

115 

. 

68 

115 

9:59 

72 

110 

Feels  as  if  about  to  sneeze.     General  head- 
ache. 

72 

115 

Disinclined  for  work.  Would  like  to  lie  down. 

10:14 

Boat  at  anchor. 

10:24 

64 

ii5 

Stomach  contents  withdrawn. 

76 

120 

76 

120 

80 

120 

10:32 

76 

120 

Headache. 

76 

120 

76 

120 

10:36 

76 

120 

Boat  rolling  at  anchor. 

76 

120 

76 

120 

72 

115 

72 

110 

72 

110 

72. 

110 

68 

110 

10:47 

72 

110 

Diffuse  headache.     Looks  worried. 

68 

105 

Boat  still  at  anchor  and  rolling-. 

76 

105 

72 

110 

68 

110 

76 

115 

10:54 

72 

110 

Lunch  of  beef  sandwiches  and  oranges. 

72 

110 

11:21 

80 

110 

Boat  starts.     Much  rolling. 

72 

110 

Dizzy.     Fulness  in  head. 

72 

110 

Headache. 

76 

110 

76 

110 

72 

115 

72 

110 

72 

105 

76 

115 

72 

115 

426  SEASICKNESS 

Remarks. 


Time, 

Pulse-  Blood- 

a.m. 

rate. 

press. 

68 

115 

72 

115 

11:35 

76 

115 

12:00 

72 

115 

72 

110 

72 

110 

72 

105 

80 

115 

76 

115 

76 

115 

76 

115 

80 

110 

76 

110 

76 

115 

76 

115 

76 

110 

p.m. 

76 

115 

12:22 

76 

115 

76 

120 

76 

115 

72 

110 

76 

115 

76 

120 

80 

120 

76 

120 

76 

125 

12:31 

76 

120 

84 

125 

80 

125 

80 

120 

80 

120 

80 

120 

12:38 

80 

120 

12:39 

76 

120 

80 

120 

76 

115 

80 

115 

80 

115 

76 

110 

76 

110 

12:46 

76 

115 

12:59 

80 

110 

76 

110 

76 

110 

80 

110 

80 

110 

80 

105 

80 

115 

Boat  at  anchor.    Walked  deck  from  11:35 

to  12 :  00. 
Boat  rolling  at  anchor. 
Headache.    Arteries  contracted. 


Annoyed  by  intermeddler. 


Boat  starts.    Headache.    Boat  rolling  much. 
Sight  of  moving  water  distresses  the  eyes. 

Dizzy.    Headache. 

Pain  in  back  of  the  neck  on  right  side. 


Arteries  contracted. 

Pain  in  left  of  epigastrium. 

Headache. 

Pain  in  eyeballs. 

Boat  rolling  and  pitching  badly. 


Boat  at  anchor  again. 
Rolling  at  anchor. 
Pain  in  epigastrium. 

Sense   of  constriction  about  lower  part  of 
chest. 


Dizzy.     Headache. 
After  walking  about. 
"Lump-sensation. " 
Headache  occipital  and  frontal. 


SEASICKNESS  427 


Time.    Pulse- Blood-  Remarks, 

p.m.      rate,  press. 

76  110 

80        95 

1 :  10     80  100      Arteries  dilated. 

80  100 

76  105 

76  105 

80  105      Fulness  in  head.     Nausea. 

80  105 

80       95      Arteries  dilated. 

80       90 

80        90 

80        90      Pain  in  epigastrium. 

80       90      Sense  of  band  about  lower  part  of  chest. 

80  100 
1:22     80       90 

80       90 

80       95 

80  105      Biparietal  headache.     Feels  very  tired. 

80  105 

80       95 

80       95 

76        85 
1 :  31     80       95 

80       95 

76       95 

76       95      Headache.     Dizzy. 

76  105 

76  100      Rolling  much. 

76  110      Arteries  contracted. 

76  110 

76  110 

72  110      Headache.     Dizzy. 

1 :  44     76  115      Annoyed  by  intermeddler. 

80  110      Angry  and  irritable.     Muscles  trembling  all 
over. 

76  115 

80  100 

80       95 

80       95      Severe  headache. 

76  100      Eructations.     Stomach  feels  well. 

80  100 
1:53     80       95      Headache. 

80       95 

80  100 

80  100 

80       90      Taking  deep  breaths. 

80  100      Frontal  headache. 
2:00     84       90      Headache.     Eructation. 

76       90      Stomach  feels  well. 

80       95 


428  SEASICKNESS 


Time,    Pulse- Blood-  Remarks, 

p.m.      rate,  press.  *vciiic«n.o. 

2:05     80  95      Boat  starts. 

80  100 

2 :  07     80  100      Boat  stops. 

84  100      Feels  weak.     Perspiring  freely. 

84  95      Eructation.     Arteries  dilated. 

84  95      Tired  and  weak. 

84  95      Would  like  to  rest  head  on  something. 

2 :  27     76  100      Walked  about  from  2 :  14  to  2 :  27. 

76  100      Felt  weak  and  tremulous  in  muscles. 

72  110      General  wretchedness. 

72  110      Boat  steady  and  still  at  anchor. 

76  110 

80  110 

2 :  35     84  115      Boat  started  for  home. 

76  105 

80  95 

80  100 

80  100 

76  90 

80  100      Headache. 

80  90      Taking  deep  breaths. 

76  90 

80  95 

80  100 

80  100 

80  100 

80  100 

2:55     76  100      Headache. 

76  100      Odour  of  tobacco-smoke  offensive. 

80  100 

3 :  00     80  100 

76  100      Boat  moving  smoothly. 

80  105      Fresh  cool  breeze.     Headache. 

72  100 

76  100 

72  100 

76  100 

76  105 

76  105 

3 :  15     80  100      Cool  breeze  on  occiput. 

76  100 

80  95      Headache  persists. 

80  95 

80  95 

80  90 

76  110 

80  110      Arteries  contracted. 

80  110      Feels  better  and  brighter. 

3 :  23     76  110      Boat  going  smoothly. 

76  110      Headache  almost  gone. 


SEASICKNESS  429 


Time,    Pulse- Blood-  Remarks, 

p.m.      rate,  press.  xvcuic«n.o. 

84  105 

80  100      Headache  bad  again. 

80  100 

80  100      Pain  through  eyeballs. 

76  100 

3:30     80  110 

72  110      Headache. 

72  110      Not  so  tired  now. 

84  110 

76  105      Occipital  headache. 

3:36     80  100 

3 :  44     68  110      After  walking  in  the  open  air. 

76  100 

80  110      Throbbing  frontal  headache. 

76  100 

72  110 

76  110 

72  100 
3:50  76   95   Coronal  headache. 

76  110 

76  110 

3 :  55  76  105   Pain  in  back  of  neck,  right  side. 

76  105 

76  100      Arteries  contracted.     Face  pale. 

80  100      Deep  breaths. 

76  105      Pain  in  occiput  and  right  side  of  neck. 

4:00     76  105      Feeling  wretched. 

4 :  01     80  110      Right  hemicrania,  especially  over  right,  su- 
perior curved  line  of  occipital  bone. 

76  105 

76  105 

4 :  05     80  105      Taking  deep  breaths. 

76  105      Dull  ache  in  eyeballs. 

76  100      Looking  at  things  causes  occipital  ache. 

76  100 

76       95 

4 :  10     80  100      Pain  all  over  scalp,  but  worse  on  right  side. 

72  105 

80  100      Sweating.     Eructations. 

76  100      Would  like  to  lie  down. 

80  100      Would  like  to  let  eyelids  droop. 

4 :  15     80  100      Closing  eyes  causes  distress. 

76  100 

76  100 

76  100 

80  100      Lump-sensation  in  stomach. 

72  105      Eructations. 

76  100      Headache  in  right  parietal  region. 

4:21     76  100 

4 :  26     76  110      After  walking  about. 


480 


SEASICKNESS 


Time, 

Pulse-  Blood- 

p.m. 

rate. 

press. 

72 

110 

4:28 

72 

110 

76 

110 

4:30 

76 

100 

72 

105 

4:32 

76 

105 

76 

105 

76 

105 

76 

110 

4:35 

76 

105 

76 

115 

76 

105 

4:38 

76 

110 

76 

100 

76 

100 

. 

76 

100 

80 

100 

4:42 

72 

115 

80 

110 

4:44 

80 

100 

80 

100 

80 

110 

4:46 

76 

110 

4:47 

, , 

•  •  • 

Remarks. 


Headache  across  top  of  head. 

Lump-sensation. 
Deep  breaths. 
Occipital  headache. 
Sweating.     Feels  weak. 
Lump-sensation  marked. 

Coronal  headache. 


Headache  not  so  bad. 

Subject  brighter  and  more  cheerful. 

Lump-sensation  persists. 

Taking  deep   breaths.     Sinking   feeling   in 

stomach. 
Arteries  contracted. 


Arteries  dilated. 
Lump-sensation.     Feels  sick. 
Occipital   headache  in  region 


of  hat  band. 


6:36 


Just  before  landing.  Some  congestion 
around  the  periphery  of  drum  membranes 
and  along  the  handle  of  the  malleus. 

Occipital  headache  persists,  i.e.,  nearly  two 
hours  after  landing. 


Protocol   4. — On  "  B "   aboard  tlie  motor  launch   "  Maggie," 
May  31,  1909.    Trip  lasting  1  hour. 


5:25 


96 

105 

96 

105 

96 

100 

72 

130 

80  125 

84  120 

76  120 

80  120 

84  120 


Standing  after  hard  day's  work. 
Feet  heavy  and  tired. 

Lying  supine.  Face  flushed.  Pupils  moder- 
ately dilated.     Room  dark. 

Lying  supine.  Face  flushed.  Pupils  moder- 
ately dilated.     Room  dark. 

Lying  supine.  Face  flushed.  Pupils  moder- 
ately dilated.     Room  dark. 

Lying  supine.  Face  flushed.  Pupils  moder- 
ately dilated.     Room  dark. 

Lying  supine.  Face  flushed.  Pupils  moder- 
ately dilated.   Room  dark. 

Lying  supine.  Face  flushed.  Pupils  moder- 
ately dilated.     Room  dark. 


SEASICKNESS  431 


Pulse-  Blood- 
rate,    press. 


Remarks. 


84  120  Lying  supine.     Face  flushed.     Pupils  moder- 
ately dilated.     Room  dark. 

108  105  Standing.  Pupils  normal  but  illumn'n  better. 

88  105 

92  105 

96  105  Boarded  launch  and  started. 

88  105  Fresh  cool  breeze.     Vibration  in  feet.    Feels 

well. 

76  100 

84  105 

84  110  Arteries  small.    Feels  well.    Water  smooth. 

88  110 

84  110  Feels  fresh  and  cool  in  breeze. 

88  95  Taking  deep  breaths. 

92  95  Slight  feeling  of  distress  in  head. 

92  95  Perspiring  along  spine. 

88  95  Lump-sensation.     Feels  a  little  sick. 

88  95 

88  95 

88  90 

88  115  After  turning  north.     Boat  pitching  much. 

88  100  Lump-sensation.     Taking  deep  breaths. 

88  95  Head  feels  well. 

88  105  Arteries  contracted.     Head  feels  cool. 

88  105  Slight  lump-sensation.     Feels  well. 

88  110  Arteries  contracted. 

84  100  Lump-sensation. 

84  95  Slight  distress  in  head. 

80  100  Lump-sensation.     Eructations. 

84  95  Arteries  small. 

84  95 

80  95 

80  95  Cool  breeze.     Feels  well  but  has  lump-sen- 
sation. 

88  95  Vibration  does  not  annoy  now. 

80  90  Arteries  much  contracted. 

76  95  Taking  deep  breaths. 

80  95  Feet  tired,  heavy  and  aching. 

80  95  Lump-sensation. 

80  100               "                     Taking  deep  breaths. 

80  105  Just  before  landing. 

80  105  Landed. 

76  115  1  min.  after  landing. 

92  115  2            "                        Feels  well. 

80  115  Drank  ginger  ale,  Iviii. 

84  120  1  min.  later. 

88  115  2 


432 


SEASICKNESS 


Protocol  5. — On  "B"  aboard  steamship  "Caledonia.'* 
Transatlantic  trip  commenced  June  26,  1909. 


Time, 

Pulse-  Blood- 

Remarks. 

p.m. 

rate. 

press. 

2:07 

84 

130 

Lying,  after  exertion,  on  board  Caledonia. 

84 

125 

4  < 

76 

125 

<< 

72 

125 

(  ( 

2:22 

72 

125 

Boat  starts. 

84 

120 

<  ( 

88 

115 

Standing. 

2:23 

84 

115 

<  < 

88 

115 

<  ( 

2:55 

68 

115 

Lump-sensation  in  stomach. 

3:09 

72 

115 

Lying.    Odour  of  tobacco-smoke  offensive. 

72 

110 

Saliva  increased. 

72 

110 

"          Occipital  headache.    Arteries  small. 

72 

110 

"           Ache  behind  right  mastoid. 

3:20 

76 

95 

Standing. 

Feels  well.     Fresh  breeze  from 

port-hole. 

76 

95 

Standing. 

84 

100 

<  ( 

80 

100 

(< 

Head  feels  well. 

88 

95 

<< 

Slightly  hungry. 

80 

95 

<  ( 

Eructations, 

3:30 

80 

90 

Standing. 

Masklike  feeling  in  scalp. 

4:40 

84 

100 

<  ( 

Tobacco-smoke  not  offensive. 

84 

100 

<< 

Slightly  dizzy. 

4:44 

80 

100 

<( 

4:45 

68 

110 

Lying.     Arteries  dilated. 

72 

110 

<< 

(< 

68 

110 

«( 

«< 

68 

110 

<( 

68 

105 

(( 

68 

105 

<( 

68 

105 

<< 

68 

105 

( ( 

4:55 

80 

90 

Standing, 
small. 

Pulse-rhythm  irregular.  Arteries 

76 

95 

Standing. 

84 

95 

<  < 

5:00 

84 

100 

<  < 

5:19 

88 

90 

<  < 

Slightly  dizzy  and  faint. 

5:21 

80 
80 

95 
95 

Standing. 
<  < 

7:00 

,  ^ 

•  •  • 

Dinner.    K  I  aborption  test  reacted  in  2  hours 

17  min. 

Salol  motility  test  reacted  in  2 

hours  22  min. 

7:23 

76 

115 

Lying. 

72 

115 

Feels  well 

.     Lying. 

SEASICKNESS 


4Be 


Time,    Pulse-  Blood- 
p.m.      rate,    press. 


8:14 
8:15 


8:21 
8:32 


8:39 
8:40 


8:56 
10:41 


72 
72 
72 
72 
76 
72 
72 
72 
76 
80 
76 
76 
76 
72 
V2 
72 
76 

68 
76 
72 
72 

76 

72 
84 
84 
88 
88 
88 
84 
68 

68 
76 
68 
72 
88 
92 
84 
84 
76 


115 
115 
125 
125 
125 
120 
115 
115 
115 
115 
120 
115 
115 
115 
115 
115 
115 

115 
115 
115 
110 
115 
115 
115 

95 
100 

90 
100 
100 
120 

115 

115 

115 

115 

95 

85 

85 

95 

95 


Remarks. 

Lying.     Conscious  of  stomach  movements. 
Slight  lump-sensation. 
Head  feels  well. 


Arteries  larger. 

Slight  lump-sensation. 

Saliva  free  all  through  K  I  tests. 


Lying. 

ach. 

Lying. 


Biparietal  headache. 

Artery  large. 

Marked  "lump-sensation"  in  stom- 


Lump-sensation  marked. 


Standing.     Eructation.     Flatus. 
"  Momentary  lightness  in  head. 

"  Lump-sensation  not  so  manifest. 


Lying.     Lump-sensation  in  throat  and  stom- 
ach. 
Lying.     Port-hole  has  just  been  closed. 


Standing.     Sweating.     Cabin  warm. 


Went  to  bed.    Slept  well  but  dreamed  much. 


Protocol  6. — On  "B."    Second  day  at  sea  on  "Caledonia," 

June  27,  1909. 
a.m. 

6 :  44     72      105      Lying  in  bed  before  arising. 

72      105 
6:46     68      110 


484 


SEASICKNESS 


Time, 

Pulse- 

Blood- 

Remarks. 

a.m. 

rate. 

press. 

6:47 

88 

90 

Standing.     Feels  well. 

84 

100 

Cool  breeze  from  port-hole. 

6:49 

84 

105 

7:05 

88 

95 

"            3  min.  after  cold  plunge. 

84 

95 

7:07 

88 

95 

7:40 

68 

115 

Lying.     Feels  well.     Face  flushed. 

72 

115 

Pupils  moderately  dilated. 

72 

120 

"          Conjunctivae  normal. 

68 

130 

68 

125 

72 

125 

7:47 

68 

125 

7:55 

84 

105 

Standing. 

84 

100 

80 

105 

76 

95 

7:59 

72 

100 

9:56 

92 

105 

Feels  well,  but  is  a  little  tired. 

88 

100 

92 

95 

10:04 

92 

95 

10:05 

76 

120 

Lying.     Congestive  headache. 

80 

120 

"          Pupils  slightly  dilated. 

80 

120 

"          Slight  lump-sensation. 

76 

120 

"          Right  frontal  headache. 

76 

125 

80 

120 

"          Slight  stomach  distress. 

10:11 

80 

120 

10:18 

76 

115 

Slight  headache.     Arteries  dilated. 

10:20 

80 

90 

Standing.    Eructation.    Lump-sensation  less. 

10:22 

92 

95 

<  < 

p.m. 

92 

95 

"           Arteries  moderately  dilated. 

12:21 

76 

110 

**          After  walking  in  cool  breeze. 

76 

105 

"  Lump-sensation  in  stomach  and 
throat. 

76 

105 

Standing. 

76 

110 

<  < 

12:25 

72 

105 

12:57 

72 

95 

"           After  making  analysis  in  cabin. 

72 

95 

"           Arteries  small. 

1:00 

72 

95 

"           Lump-sensation. 

1:01 

68 

110 

Lying.  Fulness  in  head.  Artery  moderately 
large. 

68 

105 

Lying. 

64 

105 

<  < 

68 

115 

<  < 

1:07 

68 

110 

<  < 

1:08 

72 

85 

Standing.     Blood-pressure  rose  to  120  from 

effort,  but  instantly  fell  to  85. 


SEASICKNESS 


435 


Time, 

Pulse 

•  Blood 

p. 

m. 

rate. 

press. 

72 

90 

1 

:10 

76 

95 

2 

:02 

•• 

... 

4 

.15 

68 

105 

68 

100 

72 

100 

4 

21 

68 

100 

4 

36 

68 

100 

68 

100 

64 

100 

64 

95 

4 

41 

68 

100 

4 

42 

68 

110 

64 

110 

60 

115 

4 

45 

68 

120 

4 

46 

60 

115 

60 

115 

64 

120 

60 

115 

4 

56 

64 

115 

4 

57 

64 

130 

68 

105 

68 

100 

5 

00 

68 

100 

8 

50 

68 

90 

72 

95 

8 

52 

68 

95 

8 

53 

64 

105 

.  60 

105 

60 

115 

60 

110 

60 

110 

60 

110 

9 

03 

60 

115 

9 

04 

72 

125 

72 

90 

68 

95 

72 

95 

9 

:08 

72 

90 

9 

:35 

,  , 

•  •  • 

Remarks. 

Standing. 

Dinner.     K  I  absorption  test  reacted  in  21 

minutes. 
Standing  after  walking  in  cool  breeze. 
Arteries  small. 


Arteries  small.    Feels  well. 


Lying.    Feels  well. 


Fulness  in  head. 

Slight  headache. 

Lump-sensation  in  stomach. 

Right  occipital  pain. 

Feels  sleepy. 
On  standing  up. 
Standing.     Feels  a  little  better  standing. 


After  walking  in  the  air. 
Feels  well,  but  is  tired. 


Lying.  Face  flushed  and  hot. 

*  *  Conscious  of  respiratory  movements. 

"  Lump-sensation  in  stomach. 

"  Pupils  slightly  dilated. 

"  Conjunctivae  normal. 

*'         Feels  sleepy. 
On  standing  up.     Blood-pressure  instantly 

fell  to  90. 
Standing.     Sleepy. 

"  Arteries  moderately  large. 

"  Lump-sensation  occasionally. 

Went  to  bed.    Was  awakened  by  indigestion, 
which  soon  disappeared, 


436 


SEASICKNESS 


Protocol  7.— On  "B." 


Third  day  on  "Caledonia." 
28,  1909. 


June 


Time, 

Pulse-  Blood- 

Remarks. 

a.m. 

rate. 

press. 

7:05 

80 

115 

Lying 

in  bed. 

64 

115 

<  < 

<  i 

7:07 

64 

115 

<  < 

<( 

7:08 

80 

105 

Standing. 

80 

110 

" 

7:11 

80 

105 

<  ( 

7:12 

80 

95 

<  ( 

Before  cold  tub. 

7:13 

72 

140 

Lying  after  getting  into  cold  tub. 

7:13i 

72 

135 

<  < 

Still  in  cold  tub. 

8:00 

72 

105 

Standing  after  dressing. 

8:01 

76 

100 

<  < 

Feels  well.     Arteries  small. 

8:02 

68 

120 

Lying. 

64 

125 

<  < 

64 

120 

<  < 

8:05 

64 

120 

<  < 

80 

110 

Standing.     Arteries  small. 

76 

105 

<  < 

76 

110 

<  ( 

p.m. 

1:07 

72 

100 

( < 

after  sitting  in  the  air. 

72 

100 

<( 

1:10 

72 

100 

t* 

1:11 

64 

105 

Lying. 

1:14 

64 

110 

<  < 

1:15 

64 

110 

Standing.     Feels  well. 

76 

110 

4 

72 

100 

t 

1:17 

72 

115 

H 

1:56 

76 

110 

< 

after  dinner. 

76 

115 

( 

80 

105 

< 

1:59 

76 

105 

< 

3:40 

68 
76 
76 
76 

105 
110 
100 
100 

( 
< 
( 

< 

after  being  on  deck. 

80 

120 

< 

Sneezed. 

80 

120 

< 

80 

120 

< 

30 

UO 

f 

76 

105 

( 

3:55 

76 

105 

M 

3:56 

72 

115 

Lying. 

Face  flushed  and  hot. 

72 

115 

( < 

Feels  sleepy. 

68 

115 

*t 

Conjunctivae  slightly  congeste(| 

68 

115 

1 1 

Pupils  slightly  dilated. 

4;00 

64 

105 

H 

After  falling  asleep, 

SEASICKNESS 


437 


Time, 

Pulse- 

Blood 

p.m. 

rate. 

press 

4:01 

64 

100 

64 

105 

4:10 

64 

105 

60 

110 

60 

105 

60 

105 

64 

105 

64 

110 

64 

110 

64 

110 

60 

105 

60 

110 

64 

105 

64 

105 

64 

110 

64 

110 

64 

105 

64 

105 

4:26 

64 

105 

4:27 

60 

110 

60 

110 

64 

110 

60 

105 

60 

105 

60 

105 

60 

105 

60 

105 

60 

105 

60 

105 

60 

105 

60 

105 

60 

105 

60 

105 

4:49 

64 

110 

4:50 

60 

100 

60 

105 

60 

105 

4:54 

60 

110 

60 

110 

4:58 

72 

110 

68 

105 

68 

105 

5:03 

68 

110 

68 

110 

68 

110 

68 

110 

68 

110 

^:12 

76 

100 

72 

100 

78 

m 

Remarks. 

Lying.  Partially  roused. 

Asleep ;  face  flushed. 


Snoring.     Face  deeply  flushed. 


Not  snoring. 

Snoring.     Face  deeply  flushed. 


Snoring,     Face  flushed. 


asleep. 


Face  flushed. 


Snoring.     Deep  breaths. 


Awake. 

Skin  warm  on  awaking. 

Half  awake. 


Standing.     Cool  breeze  on  body. 
Arteries  small, 


438 


SEASICKNESS 


Time,  Pulse-  Blood- 

p.m.     rate,  press. 

5 :  15     72  100 

10 :  23     76  105 

76  100 

10 :  25     72  100 

10 :  26     68  115 

64  115 

64  115 

10:28     64  115 


Remarks. 


Standing. 


Lying.     Face  flushed  and  hot. 
"  Pupils  moderately  dilated. 

"  Conjunctivae  normal. 


Protocol  8. 


-On  "B,"  aboard  the  "Caledonia." 
June  29,  1909. 


Fourth  day. 


a.m. 

7:00 


12 
13 


7:15 
7:29 


7:35 
7:36 


7:40 
10:06 


10:12 
10:13 


76 
72 
76 
84 
92 
84 
68 
68 
68 
64 
64 
80 
84 
72 
76 
84 
68 
76 
80 
88 
84 
76 
68 
68 
64 
72 
72 
72 
68 
76 
68 
72 
72 
72 
68 
72 


120 
120 
120 
110 
110 
105 
130 
130 
130 
125 
130 
120 
95 
110 
110 
105 
90 
95 
105 
100 
105 
100 
120 
120 
115 
120 
130 
120 
120 
120 
120 
120 
120 
120 
125 
120 


Lying  in  bed.     Cold  breeze  on  arms. 

"        "  Weather  foggy  and  cold. 

"        "  Ship  rolling  much. 

Standing  in  cool  breeze. 


Lying  after  cold  tub. 
"     Cool  breeze  from  port-hole. 


Standing. 


in  cool  cabin. 

Breeze  from  port-hole. 


Lying.     Fulness  in  head. 


Occipital  headache. 
Weather  cold.     Dark  day. 
Feels  chilly. 
Sleepy.     Disinclined  to  get  up. 


SEASICKNESS 


439 


Time,    Pulse-  Blood- 
a.m.      rate,    press. 


Remarks. 


10:45 
10:46 


10:52 

p.m. 

12:35 


12:39 
12:&1 

12:53 


72 
72 

76 
76 

72 
72 
80 
84 
80 
84 
80 
84 
80 

76 
76 
80 
80 
80 
72 
76 
68 
64 
64 
60 
60 
60 
64 
68 
68 
68 
72 
76 
76 
76 


1 :  09  72 

6 :  48  76 

84 

84 

84 

88 

6 :  56  84 

6 :  57  80 

80 

76 

76 

7 :  04  76 

7:05  88 

84 


01 
02 
04 
05 


120 
120 
120 
125 
125 
120 
110 
110 
100 
100 
105 
100 
100 

90 

90 

90 

95 

95 

95 

100 

125 

125 

125 

125 

125 

125 

120 

120 

125 

120 

115 

90 

90 

90 

90 
105 
105 
105 
105 
110 
110 
130 
130 
130 
125 
125 
120 
100 


Lying. 


Standing.     Headache  better. 

Some  fulness  in  head  still. 

Slight  headache. 

Feels  chilly. 

Occipital  pain  and  tenderness. 
Eyes  heavy,  weak  and  aching. 
Paraesthesias  of  scalp. 
Fulness  in  mastoid  areas. 
Forehead  hot.     Hands  cold. 


Lying.     Drowsy.     Fulness  in  head. 
Face  flushed.     Feet  cold. 


Headache.     Face  flushed. 


Standing.     Headache  better. 

Some  fulness  in  head. 
Eyes  ache  and  feel  heavy. 
Absorption  and  motility  tests  re- 
acted in  2  hours  16  min. 

After  dinner.     Feels  well. 


Lying.  Fulness  in  head,  especially  at  vertex. 
Face  flushed. 
"        Pupils  normal. 


Standing.    Fulness  in  ears. 


440 


SEASICKNESS 


Time, 

Pulse-  Blood- 

Remarks. 

p.m. 

rate,    press. 

76      105 

Standing.     Frontal  headache. 

84      100 

"           Dizzy.    Lump-sensation  in  stom 

88      110 

"                                                          [ach 

84      110 

88      110 

7:17 

84      110 

10:10' 

72      105 

"           After  walking. 

76      105 

"           Feels  well.     Skin  in  a  glow. 

10 :  13 

76      105 

10:14 

76      125 

Lying  in  bed. 

72      130 

<  < 

68      125 

<< 

10:17 

68      130 

<  < 

Slept  well.  Port-hole  closed  because  of  rough 
weather. 


Protocol  9.— On  "B."    Fifth  day  out  on  "Caledonia." 
June  30,  1909. 


6: 

50 

64 

125 

68 

120 

68 

120 

68 

125 

7: 

00 

68 

125 

7: 

01 

80 

120 

72 

100 

76 

110 

76 

110 

7 

'05 

76 

110 

7 

16 

76 

110 

76 

110 

76 

105 

7 

20 

76 

110 

7 

.21 

68 

125 

68 

125 

64 

125 

7 

:25 

64 

125 

7 

:26 

76 

125 

76 

115 

76 

110 

80 

120 

72 

120 

7 

:31 

76 

110 

9 

:48 

80 

105 

88 

100 

84 

100 

80 

100 

9 

:58 

80 

100 

Lying  in  bed.     Feels  well.     Slight  coryza. 
' '        Face  and  hands  slightly  eczematous. 


Standing.    Arteries  very  small. 


2  min.  after  cold  tub. 


Lying.     Slight  fulness  in  head. 


Standing.     Ship  rolling  considerably. 


Slight  headache. 


SEASICKNESS 


441 


Time, 

Pulse-  Blood- 

Remarks. 

a.m. 

rate. 

press. 

9:59 

72 

120 

Lying.     Feels  sleepy. 

72 

120 

<  < 

72 

120 

<  < 

10:02 

68 

120 

Ship  rolling  and  pitching. 

84 

105 

Standing.     Slight  headache. 

84 

115 

Feels  heavy  and  dull. 

80 

100 

' '           Lightness  in  head. 

84 

100 

10:07 

84 

105 

p.m. 

1:14 

76 

95 

"           Before  dinner.     Arteries  small. 

80 

105 

1:16 

72 

95 

2:06 

80 

100 

After  dinner.     Feels  well. 

2:07 

80 

105 

' '  Absorption  test  reacted  in  3  hours 
24  minutes. 

5:55 

64 

95 

"           Feels  well,  but  has  indigestion. 

72 

105 

"           Lump-sensation. 

68 

105 

5:58 

68 

105 

10:05 

76 

95 

Slight  headache.  Lump-sensation. 

72 

105 

"  Fulness  in  ears  made  worse  by 
moving  head. 

72 

95 

68 

95 

72 

100 

68 

95 

68 

100 

68 

95 

68 

95 

"           Lightness  and  fulness  in  head. 

68 

90 

72 

100 

"  Feels  as  if  top  were  being  raised 
off  head. 

76 

95 

"           Indigestion. 

10:21 

72 

100 

"           Eyes  aching. 

10:22 

64 

120 

Lying.     Saliva  increased. 

56 

115 

"          Lump-sensation  in  throat. 

64 

115 

"          Fulness  in  ears,  especially  in  right. 

60 

115 

10:26 

60 

115 

"          Ship  rolling  and  pitching. 

10:30 

60 

115 

10:31 

60 

115 

"          Ship  rolling  mainly. 

10:32 

60 

115 

Standing.     Lump-sensation  comes  and  goes» 

68 

105 

"            Tinnitus  aurium. 

72 

105 

"           Burning  sensation  in  stomach. 

72 

105 

68 

95 

72 

95 

"           Lump-sensation  in  tbroat. 

76 

100 

10:40 

^ 

105 

**           Stomach  irrigated. 

442 


SEASICKNESS 


July  1,  1909. 

Time, 

Pulse-  Blood- 

Remarks. 

a.m. 

rate. 

press. 

12:15 

72 

110 

Standing.     Feels  well. 

72 

100 

"           Burning  sensation  in  stomach  still 

72 

100 

12:18 

76 

100 

<  < 

12:19 

64 

120 

Lying  in  bed.     Lump-sensation  in  throat. 

56 

120 

1  <         << 

60 

120 

<i         (< 

12:22 

64 

120 

<<         <( 

Protocol 

10.- 

On  "B."    Sixth  day  out  on  "Caledonia." 

July  1,  1909. 

a.m. 

8:33 

76 

120 

Lying  in  bed. 

72 

120 

<  <         <  ( 

72 

120 

( (         (1 

8:36 

68 

120 

<  <         <  < 

8:37 

88 

110 

Standing.     Ship  rolling  about  badly. 

96 

90 

"           Feels  weak. 

96 

90 

88 

90 

'*           Respiration  irregular  and  rapid. 

88 

85 

"           Lightness  in  head. 

92 

95 

**           Arteries  large. 

96 

90 

*•  Fulness  in  ears,  especially  behind 
right  mastoid. 

96 

90 

92 

95 

104 

105 

"           Exercised.    Chinned  bar  3  times. 

104 

95 

'*  Conscious  of  respiratory  move- 
ments. 

8:49 

84 

95 

"           Muscles  weak  and  tremulous. 

9:10 

92 

90 

"           After  shaving.  Ship  rolling  badly. 

96 

90 

"            Has  to  hold  on  to  berth. 

92 

85 

"            Stomach  feels  well. 

92 

95 

"           Sense  of  weight  in  head. 

92 

90 

**            Eructations. 

92 

90 

"            Lump-sensation  in  stomach. 

92 

85 

"           Saliva  free.  Numbness  in  occiput. 

88 

95 

88 

95 

Feels  weak. 

9:21 

88 

95 

9:22 

76 

130 

Lying.     Arteries  moderately  contracted. 

72 

135 

Respirations  14  to  minute. 

72 

135 

"          Fulness  in  head. 

72 

125 

"          Slight  lump-sensation  in  stomach. 

68 

125 

"          Headache  in  right  temple. 

68 

125 

Face  flushed. 

^8 

120 

•'         Conjuntivse  congested. 

SEASICKNESS 


443 


Time, 

Pulse-  Blood- 

Remarks. 

a.m. 

rate. 

press. 

68 

125      Lying-.     Saliva  free. 

76 

120 

72 

125 

68 

125 

72 

120 

68 

125 

72 

120 

Respirations  18  to  minute. 

9:48 

72 

125 

Lump-sensation  in  stomach. 

9:49 

88 

100 

Eructations. 

84 

95 

Lightness  in  head  behind  right  ear. 

88 

95 

Numbness  behind  right  ear. 

88 

95 

Respirations  16  to  minute. 

88 

95 

Ship  rolling  badly. 

92 

95 

Feels  fairly  well. 

10:04 

88 

90 

Respirations  24  to  the  minute. 

p.m. 

12:50 

72 

130 

After  making  analysis. 

72 

130 

Fulness  in  head.     Skin  moist. 

76 

130 

Sleepy.     Respirations  16. 

72 

125 

Lightness  in  left  ear. 

12:58 

72 

125 

Slight  headache.     Weight  on  top  of 
head, 
ding.    Feels  dizzy  and  weak. 

12:59 

88 

110      Stan 

88 

90 

'           Tremulousness  all  over  body. 

88 

95 

'           Fulness  and  lightness  in  ears. 

92 

95 

'           Coronal  headache. 

92 

90 

1:04 

92 

95 

4:40 

84 

105 

Feels  weak.     Sweating. 

84 

100 

*           Eyes  heavy  and  aching. 

84 

105 

'           Lump-sensation  in  stomach. 

84 

100 

88 

95 

4:48 

88 

100 

'           Ship  rolling  badly. 

4:49 

68 

115      Lyin 

g.     Fulness  in  head. 

72 

120 

Face  flushed. 

68 

120 

Sleepy. 

64 

120 

Great  relief  to  lie  down. 

68 

115 

Eyes  heavy. 

68 

115 

Respirations  22. 

68 

115 

64 

120 

60 

120 

64 

120 

64 

120 

64 

115 

72 

110 

68 

115 

64 

115 

68 

115 

444 


SEASICKNESS 


Time, 

Pulse-  Blood 

p.m. 

rate. 

press. 

68 

105 

72 

115 

68 

100 

72 

115 

68 

115 

72 

115 

72 

105 

72 

115 

72 

110 

64 

115 

68 

115 

5:54 

68 

115 

5:55 

80 

125 

80 

105 

80 

110 

80 

110 

84 

90 

88 

95 

84 

95 

6:20 

•• 

•• 

9:34 

84 

95 

84 

90 

76 

100 

80 

100 

84 

100 

84 

105 

80 

105 

84 

100 

9:45 

84 

100 

9:50 

72 

120 

72 

120 

68 

120 

68 

115 

9:55 

68 

120 

Remarks^ 


Lying. 


Standing. 


Feels  well. 
Slight  headache. 
Ship  rolling  badly. 
Numbness    and    burning 
ciput. 


in  oc- 


Dinner  over.     Absorption  test  reacted  in  37 

minutes. 
Standing  after  walking  on  deck. 

Irritable  and  worrisome. 


Feels  well. 


Lying  in  bed.     Slight  frontal  headache. 
"      Pain  through  right  eye. 
"      Pain  in  muscles  of  occiput,  right  side. 


Ship  rolling  badly. 


Protocol  11.— On   "  B."    Seventh  day  out  on  "Caledonia." 

July  2,  1909. 


Lying  in  bed.     Feels  well. 


a.m. 

6:47 

72 

125 

76 

125 

68 

120 

6:54 

68 

125 

6:55 

,  , 

110 

88 

95 

72 

90 

84 

90 

Standing.     Lightness  in  head. 
Feels  well. 


SEASICKNESS 


445 


Time, 

Pulse-  Blood- 

a.in. 

rate. 

press. 

6:59 

84 

105 

7:00 

,  , 

7:27 

84 

95 

96 

90 

92 

90 

7:30 

88 

85 

7:31 

84 

120 

72 

130 

68 

120 

7:34 

67 

120 

8:00 

68 

130 

72 

130 

68 

130 

8:04 

68 

130 

8:05 

68 

110 

76 

100 

76 

95 

76 

90 

80 

95 

80 

95 

8:11 

88 

95 

8:56 

80 

100 

84 

95 

76 

95 

8:59 

80 

95 

p.m. 

12:20 

80 

100 

76 

100 

76 

100 

80 

100 

84 

100 

12:26 

80 

100 

12:27 

80 

120 

72 

120 

72 

125 

68 

120 

72 

125 

64 

120 

12:35 

64 

125 

12:36 

68 

100 

80 

100 

80 

105 

76 

100 

12:40 

76 

100 

12:46 

76 

100 

88 

105 

92 

90 

84 

95 

Remarks. 

Standing. 
Cold  tub. 
Standing.     Longs  to  sit  or  lie  down. 


Lying. 


Throat  tickled.     Cough  suppressed. 


Slight  headache. 
Eyes  heavy.     Sleepy. 


Standing.     Numbness  in  scalp. 
Ship  rolling  heavily. 
Feels  well. 

Conscious  of   respiratory  move- 
ments. 


Ship  rolling.    Balancing  efforts. 


After  3  hours  on  deck  walking 

and  sitting  in  cool  air. 
Feels  well. 
Artery  contracted. 


Lying.     Arteries  moderately  dilated. 
Respirations  18. 
Feels  well.     Sleepy. 


Standing.     Arteries  well  contracted. 


After  effort  at  balancing. 
With  eyes  closed. 

Arteries  dilated. 


446 


SEASICKNESS 


Time, 

Pulse-  Blood- 

Remarks. 

p.m. 

rate. 

press. 

12:51 

92 

95 

Standing. 

2:52 

88 

130 

Lying. 

Suppressed  a  sneeze. 

76 

125 

<  ( 

Arteries  moderately  large. 

76 

120 

<  < 

Respirations  22  at  first,  later  22. 

76 

125 

( < 

72 

120 

<( 

72 

115 

<  < 

76 

125 

3:01 

72 

120 

3:02 

76 

95 

Standing.     Feels  well. 

3:03 

92 

90 

Arteries  large. 

3:04 

92 

84 
92 

88 

90 

100 

95 

95 

3:08 

92 

95 

4:30 

80 

80 
76 

105 

105 
105 

After  sitting  on  deck  for  an  hour 
and  a  half. 

80 

105 

Arteries  small. 

80 

105 

4:35 

80 

105 

4:36 

84 

130 

Lying. 

Face  flushed. 

72 

130 

<  < 

Hands  cold. 

68 

125 

<  < 

68 

125 

< 

Feels  well. 

72 

125 

«< 

68 

130 

4:45 

68 

130 

<( 

4:46 

72 

105 

Standing.    Arteries  very  small. 

84 

100 

84 

105 

80 

100 

80 

105 

84 

100 

4:52 

84 

105 

After 

dinner  absorption  test  did  not  react 

positively  for  3i  hours. 

10:35 

88 

85 

Standing.     Feels  well. 

88 

85 

Arteries  very  small. 

80 

85 

92 

85 

80 

85 

80 

85 

80 

85 

80 

85 

10:45 

76 

85 

10:46 

60 

130 

Lying. 

Arteries  large. 

60 

125 

<  < 

Liver  not  enlarged  or  tender. 

SEASICKNESS 


447 


Time, 

Pulse-  Blood 

p.m. 

rate. 

press. 

60 

120 

10:49 

64 

120 

Protocol 

11a.- 

p.m. 

4:57 

84 

80 

88 

90 

80 

90 

84 

85 

84 

100 

80 

80 

80 

75 

84 

80 

5:22 

84 

80 

5:23 

80 

115 

64 

105 

56 

110 

60 

100 

52 

105 

56 

105 

60 

105 

52 

105 

56 

110 

56 

105 

5:35 

56 

105 

5:36 

56 

75 

100 

80 

88 

80 

5:42 

100 

80 

Remarks. 

Lying. 

Slight  lump-sensation    in   stomach, 
fairly  well,  but  dreamed  much. 


Slept 


-On  "S."    Aboard  "Caledonia."    Seventh 
day  out.    July  2,  1909. 

Standing. 


Lying.     Arteries  large. 

' '  Pulse-rhythm  irregular. 

Face  flushed. 
<< 

Sleepy. 


Standing. 


Protocol  12.— On  "  B."    Eighth  day  out  on  "  Caledonia." 
July  3,  1909. 


Lying   in   bed.     Slight    lump-sensation    in 

stomach. 
Lying.     Respirations  18  and   16. 


a.m. 

6:55 

68 

120 

72 

120 

72 

115 

68 

115 

7:01 

68 

115 

7:02 

88 

110 

84 

100 

80 

95 

7:05 

80 

95 

7:22 

88 

85 

92 

90 

Standing.     Lump-sensation  in  stomach. 


After  dressing. 


448 


SEASICKNESS 


Time, 

Pulse-  Blood 

a.m. 

rate. 

press. 

88 

90 

7:27 

88 

90 

7:28 

68 

120 

68 

115 

68 

115 

68 

120 

68 

120 

7:37 

72 

115 

7:38 

84 

85 

84 

85 

84 

85 

88 

90 

7:42 

84 

95 

7:51 

88 

90 

84 

90 

88 

95 

92 

95 

7:55 

92 

95 

7:56 

76 

125 

80 

125 

72 

125 

68 

125 

72 

120 

72 

115 

68 

115 

8:09 

68 

115 

8:10 

92 

95 

88 

90 

92 

90 

88 

90 

88 

95 

8:15 

84 

90 

11:58 

68 

85 

84 

85 

80 

90 

76 

90 

p.m. 

12:05 

80 

90 

12:06 

68 

115 

64 

105 

68 

115 

60 

110 

60 

115 

12:10 

84 

105 

12 :  11 

72 

90 

76 

90 

76 

95 

12:14 

76 

90 

Remarka. 


Standing. 


Lying.     Respirations  20. 

Lump-sensation  in  stomach  slight. 


Standing. 


After  stomach  irrigation. 
Lump-sensation      persists      in 
stomach. 


Lying.     Fulness  in  ears. 

Lump-sensation  in  stomach  persists. 
Arteries  large. 
Respirations  20. 


Standing.    Respirations  16. 

"  Raw  feeling  in  fundus  of  stom- 

ach. 
Arteries  large. 


After  sitting  on  deck  in  cool  air. 


Lying. 


Standing.     Arteries  small. 


SEASICKNESS 


449 


Tfane. 

Pulse- 

Blood 

p.m. 

rate. 

press 

1:38 

•• 

•• 

1:50 

92 

95 

96 

59 

92 

95 

88 

95 

96 

90 

1:56 

92 

95 

1:57 

76 

125 

76 

125 

76 

120 

80 

115 

76 

120 

76 

120 

72 

115 

2:31 

72 

120 

80 

115 

80 

115 

76 

115 

2:35 

76 

115 

72 

115 

72 

120 

80 

125 

76 

115 

80 

115 

2:43 

76 

115 

72 

115 

72 

115 

2:50 

68 

115 

2:51 

80 

125 

2:52 

80 

115 

2:53 

84 

85 

92 

95 

84 

95 

92 

95 

88 

95 

96 

85 

96 

85 

96 

90 

3:01 

88 

90 

4:57 

80 

90 

88 

100 

84 

90 

5:05 

84 

90 

5:06 

76 

120 

72 

120 

68 

120 

76 

115 

5:10 

72 

120 

5:11 

80 

110 

Remarks. 

Dinner  over.    Motility  test  reacted  in  1  hour 

25  minutes. 
Standing.     Fulness  in  ears. 


Lying.    Respirations  20. 


Asleep. 


Respirations  18. 
Pupils  contracted. 

Conjunctivae  congested. 


Coughed. 


"         Awoke  suddenly. 
'*         Hot  flush  along  spine  on  awaking. 
Standing.      Ship  rolling. 

Efforts  at  balancing. 

Feels  well. 

Lump-sensation  in  stomach. 


After  sitting  in  cold  air. 


Lying.     Face  flushed. 


Standing.     Feels  well. 


450 


SEASICKNESS 


Time,     Pulse-  Blood- 
p.m.       rate,    press. 


80 
84 
84 
88 
88 
88 
5 :  18  80 
5 :  35     . . 

10 :  22  80 
84 
84 
80 
84 

10 :  28     84 

10 :  29  68 
64 
64 
60 
60 
60 

10:35     64 


100 
95 
95 
95 
90 
95 
90 


90 

90 

85 

85 

85 

90 

115 

115 

125 

120 

125 

115 

120 


Remarks. 

Standing.    Slight  lump-sensation  in  stomach. 


Stomach    contents    removed.     Some    fresh 

blood. 
Standing.    After  resting  on  deck. 


Lying  in  bed.     Feels  well.     Arteries  large. 
Respirations  20. 

Slight  lump-sensation  in  stomach. 
Slight  herpes  labialis  appearing. 


Protocol  12a.— On  "  S."    Eighth  day  out  on  "  Caledonia." 


July  3,  1909. 


p.m. 
12:19 


12:25 
12:34 


12:38 
12:39 


12:43 


76 
72 
76 
76 
76 
72 
76 
60 
60 
60 


80 

85 

85 

85 

90 

95 

85 

110 

105 

105 


Standing. 


56      105 
60      105 


76 
76 
76 
76 
76 


85 
90 
90 
90 
95 


Laughed. 


Lying.    Arteries  moderately  large. 


Standing.    Arteries  moderately  contracted. 


Protocol  13.— On  "  B."    Ninth  day  out  on  "  Caledonia.*' 
July  4,  1909 


a.m. 
6:45 
7:04 


. .      Cold  tub.     Moville. 
64      125      Lying.     Ship  has  just  started  from  Moville. 


SEASICKNESS  451 

Time,   Pulse-  Blood-  r>^^„,T,„ 

a.m.      rate,  press.  Remarks. 

64  120      Lying. 

64  120 

7:06     68  120 

7:07    84  105      Standing.    Feels  well. 

88  105 

80  105 

84  105 

7:11     80  105 

7 :  54     72  120      Lying.    After  packing  suit-cases. 

76  120 

68  120 

7:57     72  120 

7 :  58    96  95      Standing.    For  a  moment  blood-pressure  was 
at  115. 

92  90      Standing. 

92  90 

92  95 

8  *  02     92  95  *  * 

9:40  112  85  "  Cabin  very  hot  and  close. 

112  90  •*  Sweating. 

108  90  "  Lightness  in  head. 

108  90 

108  80  '*  Arteries  variable,  i.e.,  small  at 

times  and  at  others  large. 

9:49  104  85 

9 :  50     76  135      Lying.    Headache.    Fulness  in  head. 

80  125         "  Respirations  24. 

80  120  "  Feels  well. 

76  115 

80  120         "         Pupils  normal. 

80  115 

84  115 

10:01     84  115 

10 :  02  112  90      Standing.     Arteries  moderately  large. 

112  85  "  Conscious  of  respiratory  move- 

ments. 

108  90 

108  85 

104  90 

108  90 

108  100 

10:09  104  90 

11:25     88  105  "  After  walking  in  cold  air  (57°  F.). 

84  95  •*  Feels  well. 

88  95 

88  85 

11:29     88  90 

11 :  30     84  105      Lying.     Arteries  larger  than  when  standing. 

76  105 

11:32    72  105         "'       Respirations  20,  22. 


452 


SEASICKNESS 


Time, 

Pulse-  Blood 

a.m. 

rate. 

press 

11:33 

76 

115 

68 

115 

11:37 

76 

115 

11:38 

84 

100 

84 

95 

84 

90 

80 

85 

92 

80 

84 

85 

84 

90 

11:45 

84 

95 

p.m. 

12:15 

100 

85 

92 

85 

92 

85 

12:19 

96 

85 

12:20 

92 

125 

80 

120 

80 

115 

80 

110 

76 

115 

12:'28 

80 

120 

12:29 

76 

85 

92 

80 

88 

85 

96 

85 

96 

85 

92 

85 

12:35 

92 

85 

12:47 

84 

12:48 

96 

12:49 

92 

12:50 

92 

12:51 

80 

3:33 

72 

95 

72 

95 

72 

90 

76 

95 

72 

90 

84 

90 

80 

85 

3:40 

76 

95 

3:41 

76 

115 

72 

115 

72 

110 

3:46 

68 

110 

3:47 

84 

95 

80 

90 

84 

95 

Remarks. 


Lying. 


standing.     Feels  well. 

Arteries  moderately  dilated. 


Feels  well. 

Arteries  moderately  large. 


Lying.    Arteries  large. 
"         Respirations  24. 


Arteries  smaller. 

Fulness  in  head.    Headache. 


Standing. 


Standing  on  deck  in  cold  air. 


After   standing    on  deck    until   feet  grew 

tired. 
Standing. 


Artef  ies  small. 


Lying.    Feels  well.    Arteries  small. 
<  < 

«« 

(< 

Standing.    Just  before  landing. 


SEASICKNESS 


453 


Time,    Pulse-  Blood- 
p.m.      rate,    press. 


Remarks. 


3:51 
3:52 
4:38 
4:39 
4:40 

4:41 
4:42 

4:47 


4:50 

4:53 
4:54 


4:59 
9:46 


9:53 
9:54 


9:57 


84 
76 

96 
88 
92 
88 
84 
92 
88 
84 
76 
72 
72 
68 
68 
68 
68 
80 
80 
88 
84 
84 
84 
92 
84 
84 
96 
88 
68 
68 
64 
68 


90 
95 

105 
105 
115 
115 
120 
110 
105 
105 
120 
115 
115 
115 
110 
110 
115 
95 
95 
100 
100 
110 
100 
95 
95 
100 
105 
95 
110 
110 
115 
115 


Standing. 


Landed  at  Stobcross  Quay,  Glasgow. 

Standing  in  hotel  room,  Glasgow. 

<  < 

Lying. 
<< 

It  I 

Standing. 

<  < 

Lying. 


Standing.    Feels  well. 


After  stroll  in  botanical  gardens. 
Arteries  moderately  contracted. 


Lying  in  bed. 


Protocol  14.— On  "B."    July  5th,  on  shore. 


8 

25 

60 

100 

64 

100 

64 

100 

8 

28 

68 

100 

8 

29 

64 

110 

64 

110 

68 

110 

64 

110 

64 

115 

64 

110 

8 

43 

64 

110 

Lying  in  bed  after  awaking. 

"  Arteries  contracted.     Room  cool. 


After  turning  from  head  to  foot  of 
bed. 


454 


SEASICKNESS 


Time,    Pulse-  Blood- 
a.m.       rate,    press. 


8:44 


8:49 
9:15 


9:22 
9:23 


9:29 
9:30 


9:34 


88 
80 
88 
84 
84 
84 
88 
88 
88 
84 
80 
64 
64 
64 
64 
60 
84 
84 
80 
80 
80 


p.m. 

5 :  55  92 

92 

96 

5 :  58  92 

5 :  59  80 

76 

72 

72 

6 :  07  72 

6:08  80 

88 

6 :  10  92 

92 

6 :  12  88 


105 
110 
110 
110 
110 
110 
100 
110 
110 
100 
105 
105 
110 
115 
115 
115 
115 
105 
105 
105 
105 
105 

120 

125 
125 
125 
125 
125 
125 
125 
120 
125 
125 
120 
115 
110 


Remarks. 

Standing.    Feels  well.    Arteries  contracted. 


After  dressing. 
Arteries  contracted. 


Lying.    Feels  well.    Arteries  contracted. 
<  < 

"         Respirations  20. 

<  I 

Standing.    Arteries  contracted. 


Before  leaving  for  train  to  catch 
Dublin  boat. 


Lying. 


Respirations  24. 


Standing.     Arteries  moderately  dilated. 


Protocol  14a. — On  "  B,"  aboard  the  steamship  "Tiger"  of 


Duke's  line  from  Glasgow  to  Dublin.    July  5,  1909. 


p.m. 

7:58 


8:02 
8:03 


108 
108 
104 
108 
108 


95 
90 
95 
100 
95 


108        95 


Standing  in  cabin.  Sweating  after  exertions. 
Cabin  hot. 
"  Temporary  lump  in  stomach. 


Boat  starts. 
Standing. 


i 


SEASICKNESS 


455 


Time, 

Pulse-  Blood 

p.m. 

rate. 

press 

8:05 

108 

95 

8:06 

92 

120 

84 

120 

84 

115 

84 

120 

84 

115 

88 

115 

84 

115 

84 

110 

80 

105 

80 

105 

80 

105 

76 

105 

80 

105 

80 

105 

84 

115 

80 

110 

8:32 

80 

115 

8:33 

96 

85 

104 

90 

96 

95 

96 

90 

96 

95 

96 

90 

92 

95 

96 

90 

100 

95 

100 

90 

100 

85 

100 

85 

96 

85 

96 

90 

100 

85 

100 

85 

100 

85 

100 

85 

96 

85 

96 

85 

100 

85 

92 

90 

96 

85 

96 

85 

96 

90 

100 

90 

100 

90 

9:05 

100 

90 

Remarks. 

Standing. 

Lying.     Slight  lump-sensation  in  stomach. 

"  Arteries  smaller  but  still  large. 

"  Fulness  in  head.     Respirations  26. 

"  Slight  pain  and  numbness  in  occiput 

on  right  side. 

**  Boat  jolts  and  trembles. 


'*         Jarring  of  body  from  head  to  foot. 
"  No  rolling  or  pitching. 

"  Arteries  large. 

"  Respirations  24. 

"  Worrying  about  trifles. 

"  Deep  respirations. 

"  Lump-sensation  in  throat. 

"  Respirations  24. 

"  Arteries  moderately  contracted. 

Standing.     Arteries  small. 

"  Slight  lump-sensation  in   stom- 

ach. 
Biparietal  headache. 
Sweating. 

Fulness    in    ears   and    mastoid 
areas. 


Headache  occipital,  right  side. 

Lightness  in  head. 

Lump-sensation  marked. 

Pupils  slightly  dilated. 

Muscles  feel  in  fair  condition. 

Numbness  in  occiput. 
Boat  pitching  somewhat. 
Much  jolting  from  machinery. 

Slight  pain  near  umbilicus. 
Occipital  numbness  and  aching 
worse  on  right  side. 


Arteries  moderately  contracted. 


456 


SEASICKNESS 


July  6,  1909. 

Time,  Pulse- 

Blood- 

Remarks. 

a.m. 

rate. 

press. 

12:10 

76 

95 

Standing.    After  walking  on  deck. 

72 

95 

<« 

Occipital  headache  worse  on  left 
side. 

72 

100 

<( 

76 

95 

i< 

72 

95 

<< 

12:15 

64 

95 

<< 

Arteries  moderately  contracted. 

12:16 

64 

120 

Lying. 

Respirations  24. 

68 

125 

Arteries  moderately  contracted. 

68 

125 

Coronal  headache. 

68 

125 

Face  flushed. 

64 

125 

Pupils  moderately  dilated. 

60 

125 

Frontal  headache. 

68 

125 

Respirations  21.    Headache.   Lump- 
sensation  in  stomach. 

6:20 

68 

110 

Lying 

in  bed  after  awaking. 

68 

110 

Arteries  moderately  large. 

72 

110 

Respirations  19. 

72 

110 

Yawning 

72 

115 

68 

115 

6:30 

68 

115 

6:31 

88 

105 

Standing.    Arteries  moderately  contracted. 

84 

95 

84 

95 

88 

100 

Arteries  moderately  contracted. 

80 

95 

84 

100 

88 

100 

84 

95 

Arteries  small. 

84 

95 

Feels  well. 

6:41 

88 

95 

7:00 

,  , 

, , 

Landed  at  the  North  Wall,  Dublin. 

Protocol  15a.— On  "B,"  aboard  the  "Lady  Wolseley"  of  the 
British  and  Irish  Steam  Packet  Company  from  Dublin 
to  Southampton.    July  10,  1909. 


p.m. 
4:54      .. 

Boat  started. 

4:55  104 

95 

Standing.    Arteries  large 

100 

95 

108 

90 

108 

90 

104 

95 

5:03  104 

95 

Standing. 

SEASICKNESS 


457 


Time. 

Pulse-  Blood- 

p.m. 

rate. 

press. 

5;04 

92 

120 

96 

120 

96 

115 

92 

115 

92 

115 

96 

115 

88 

115 

92 

105 

92 

105 

5:15 

92 

110 

5:16 

112 

95 

104 

85 

100 

95 

104 

95 

100 

90 

104 

95 

5:21 

104 

90 

6:32 

84 

95 

88 

95 

84 

105 

92 

100 

6:36 

92 

105 

7:16 

96 

100 

92 

105 

96 

105 

92 

105 

92 

100 

7:21 

92 

105 

9:55 

96 

95 

96 

95 

96 

95 

100 

95 

88 

95 

96 

90 

92 

95 

92 

90 

96 

90 

92 

90 

92 

85 

88 

85 

92 

90 

92 

85 

10:15 

92 

90 

10:16 

80 

135 

80 

135 

76 

135 

10:20 

80 

135 

Remarks. 

Lying.    Boat  steady,  but  much  vibration 

from  machinery. 
<< 

"         Arteries  large. 

**         Pupils  moderately  dilated. 


Lying.    Asleep. 


Respirations  22. 


Standing.     Arteries  moderately  large. 
Feels  well. 


Standing.     After  being  on  deck. 

Arteries  moderately  contracted. 

Weather  calm. 

After  dinner. 


Standing.     After  walking  on  deck. 
"  Fresh  breeze. 


Boat  pitching  a  little. 
Lump-sensation  and  burning  in 
stomach. 


Boat  rolling  considerably. 
Feeling  sick  at  stomach. 
Saliva  increased. 


Lying.    Great  relief  to  lie  down. 
"         Arteries  large. 
*'         Lump-sensation  in  stomach. 
*'         Respirations    24.      Sleepy.      Very 
nervous. 


458 


SEASICKNESS 


Time,  Pulse- 

Blood. 

a.m. 

rate. 

press. 

5:55 

80 

135 

76 

130 

76 

130 

76 

130 

72 

135 

76 

135 

6:15 

76 

135 

6:16 

84 

100 

84 

100 

6:18 

88 

100 

6:20 

92 

110 

88 

105 

88 

115 

92 

105 

80 

110 

6:27 

80 

115 

6:28 

80 

135 

80 

135 

76 

135 

72 

135 

72 

135 

76 

125 

6:34 

76 

130 

7:15 

•• 

•• 

8:05 

80 

125 

80 

125 

80 

125 

80 

130 

80 

135 

80 

135 

80 

135 

80 

135 

80 

135 

80 

135 

80 

135 

80 

135 

76 

135 

8:24 

80 

130 

8:25 

86 

125 

92 

110 

88 

115 

88 

115 

8:29 

88 

110 

11:00 

88 

125 

Protocol  15b.— July  11,  1909. 

Remarks. 

Lying  in  bed.    Awoke  at  4  A.M.  after  a 

stormy  night. 

**         Boat  rolled  and  pitched  furiously. 

**  Marked  "lump-sensation"  in  stom- 

ach as  boat  rolls. 

'*  Feels  dizzy  and  sick,  though  lying 
in  bed. 

' '         right  side  out  with  head  toward  bow. 

"         Pain  in  occiput  right  side. 
<< 

Standing. 


Arteries  contracted. 

Ship  rolling  badly. 

Marked  balancing  efforts. 

Lump-sensation  in  stomach. 

Saliva  increased. 

Heaviness  in  head. 
Lying.     Lump-sensation  very  marked. 
"  Mind  dull.     Sick  headache. 

"  Saliva  much  increased. 

"  Occipital  headache. 

"  Pain  in  neck. 

"         Arteries  moderately  contracted. 

Stomach  irrigated.    Mucus  and  some  fresh 

blood  removed. 
Lying.     After  test  meal. 

"  Sick,  heavy  feeling  in  head. 

"  Dull  coronal  headache. 

**  Saliva  free. 

"  Lump-sensation  in  stomach. 

"  Respirations  22. 

"  Arteries  very  small. 

"  Sleepy.     Face  flushed. 

Occipital  headache. 
Lying.     Disinclined  for  work. 

"  Irritable.     Wants  to  be  let  alone. 

"  Ship  rolling  badly. 

Standing.     Marked  efforts  at  balancing. 
Nervous.     Sweating. 

Feels  weak. 


Ship  rolling  badly. 


SEASICKNESS 


459 


Time,    Pulse-  Blood- 
a.m.       rate,    press. 

92  120 

96  110 

92  110 

11 :  04  84  105 


p.m. 

1 :  50  88 

96 

92 

88 

80 

1 :  55  92 

3 :  25  . . 

4:40  100 

92 

4 :  43  92 

9 :  43  76 

80 

80 

80 

80 

9 :  50  80 

9:51  76 

72 

68 

72 

68 

10:05  72 


105 
105 
105 
115 
105 
105 

105 
105 
105 
110 
110 
110 
105 
105 
110 
125 
125 
125 
125 
125 
125 


Remarks. 

Standing.     Much  effort  at  balancing. 
"  Arteries  contracted. 

"  Feels  weak  from  balancing. 


After  dinner.    Boat  steady  now. 
Arteries  moderately  contracted. 

Whiskey  and  soda  at  dinner. 


Alongside  pier  at  Falmouth. 

Standing  after  making  analyses. 

"        Boat  at  pier. 
<( 

'*        After  walking  on  deck. 

"        Respirations  24. 

**        Arteries  moderately  contracted. 
(< 

Feels  well. 

Lying  in  bed.    Boat  still  by  Falmouth  pier. 
Arteries  moderately  large. 

Respirations  20. 

Feels  well. 


Protocol  15  c.— July  12,  1909. 


7:45  76 

72 

72 

72 

72 

•   72 

72 

8 :  03  72 

8:04  100 

100 

96 

96 

92 

88 

92 

9 :  09  96 

9:10  80 

72 


125 
125 
120 
120 
120 
125 
120 
120 
105 
110 
105 
105 
105 
110 
105 
105 
140 
135 


Lying  in  bed  after  awaking. 

Boat  still  at  Falmouth  pier. 
Arteries  moderately  contracted. 

Respirations  22. 


Standing.     Arteries  moderately  dilated. 
Feels  well. 


Lying  after  effort  of  getting  into  berth. 
Arteries  moderately  large. 


460 


SEASICKNESS 


Time, 

Pulse-  Blood- 

a.in. 

rate. 

press. 

72 

125 

76 

125 

9:18 

80 

125 

9:19 

104 

95 

^00 

95 

96 

105 

96 

105 

96 

100 

92 

105 

9:25 

96 

100 

10:49 

92 

105 

88 

105 

92 

105 

88 

105 

92 

105 

10:55 

92 

105 

10:56 

72 

140 

72 

140 

72 

140 

76 

140 

76 

135 

76 

135 

76 

135 

76 

135 

11:11 

80 

135 

11:12 

100 

105 

88 

105 

88 

105 

84 

105 

88 

110 

88 

105 

92 

105 

88 

105 

84 

105 

11:21 

88 

105 

p.m. 

3:00 

6:00 

,  , 

7:14 

92 

lio 

96 

110 

100 

105 

7:17 

96 

105 

7:18 

76 

120 

88 

125 

88 

125 

88 

120 

88 

120 

84 

120 

7:25 

84 

120 

Bemarks. 


Lying. 


Boat  started  for  Plymouth  at  9:17 

A.M. 

Standing.     Arteries  moderately  large. 
Feels  well. 


Boat  moving  smoothly. 
Feels  well. 


Lying.    Arteries  moderately  contracted. 
"  Respirations  18,  20. 

"         Pupils  normal. 

Sleepy. 
**         Slight  "lump-sensation." 

"         Much  jolting  from  machinery. 

**  Occipital  headache. 

Standing.    Arteries  moderately  contracted. 


Slight  occipital  headache. 


Arrived  at  Plymouth.     Strolled  about  towa 
Boat  started  for  Southampton. 
Standing  after  dinner. 


Ly 


ng.     Arteries  moderately  large. 
Respirations  20. 


SEASICKNESS 


461 


Time. 

Pulse- 

Blood 

p.m. 

rate. 

press. 

7:26 

108 

95 

100 

105 

96 

105 

96 

110 

100 

105 

7:31 

96 

105 

10:42 

76 

100 

80 

105 

80 

105 

80 

105 

80 

105 

76 

105 

88 

105 

80 

105 

84 

100 

10 :  58 

80 

105 

10:59 

76 

125 

72 

125 

72 

120 

76 

120 

72 

120 

11:09 

72 

120 

Remarks. 

Standing.      Face  flushed. 

Fulness  in  head. 

Feels  stupid  and  heavy. 


After  a  bottle  of  ale. 
Slight  dizziness. 

Fulness  in  head. 


Lying  in  bed.    Fulness  in  head. 
Face  flushed. 


Slept  poorly. 


Protocol  15d.— July  13,  1909. 


5 

43 

72 

125 

72 

125 

72 

120 

76 

125 

72 

120 

72 

120 

76 

120 

5 

56 

72 

120 

5 

57 

104 

95 

96 

95 

92 

95 

88 

95 

88 

95 

88 

105 

88 

100 

92 

110 

92 

105 

96 

95 

96 

100 

88 

95 

6 

10 

88 

100 

6. 

12 

, , 

, , 

Lying    after  awaking. 

Slight  lump-sensation  in  stomach. 
Respirations  24. 


Standing.   Gliding  up'  *  Southampton  Water. ' ' 
Arteries  contracted. 

Feels  sick  at  the  stomach. 
Sweating. 

Feels  weak. 


Landed  at  Southampton. 


i62  SEASICKNESS 

Protocol  16a.— On  "B,"  aboard  the  "Southwestern"  from 
Southampton  to  Cherbourg.    July  13,  1909. 


Time,    ] 

Pulse- 

Blood- 

Remarks. 

p.m. 

rate. 

press. 

11:50 

96 

110 

Standing.     After  walking  from  the  Hippo- 
drome, i.e.,  about  |  of  a  mile. 

92 

110 

<< 

88 

120 

Cabin  stuffy. 

88 

115 

**            Arteries  moderately  contracted. 

92 

105 

tt 

92 

105 

<( 

96 

105 

July  14,1909. 

88 

105 

Standing. 

92 

110 

<  < 

a.m. 

12:01 

88 

105 

(( 

12:02 

76 

125 

Lying.     Respirations  24. 

76 

125 

"       Twitching  of  long  flexors  in  right 
wrist. 

76 

130 

<( 

76 

130 

<< 

12:06 

76 

130 

<  < 

12:11 

76 

130 

<( 

12:12 

96 

110 

Standing.     Arteries  small. 

92 

115 

Feels  well. 

92 

115 

(< 

88 

110 

t( 

92 

105 

tt 

12:20 

88 

105 

tt 

12:24 

Boat  started. 

1:37 

92 

95 

Standing.    Arteries  moderately  dilated. 

88 

105 

Feels  well. 

88 

105 

<  < 

88 

105 

tt 

88 

105 

1 1 

1:43 

88 

105 

<  < 

1:44 

76 

125 

Lying  in  bed. 

76 

130 

"      Arteries  moderately  contracted. 

72 

125 

•*      Feels  well. 

72 

125 

68 

125 

1:51 

72 

125 

6:33 

76 

125 

Lying,  after  awaking. 

76 

125 

Boat  rolling  and  pitching. 

76 

120 

Awoke  with  lump-sensation  in  stom- 
ach. 

80      120 


SEASICKNESS 


463 


Time, 

Pulse-  Blood- 

Remarks. 

a.m. 

rate. 

press. 

76 

120 

Lying. 

Saliva  free. 

80 

120 

80 

120 

6:50 

80 

120 

(( 

Feels  nervous. 

6:51 

80 

115 

Standing. 

Some  balancing  efforts. 

92 

120 

<  i 

Marked  lump-sensation. 

96 

115 

96 

110 

<  ( 

Feels  weak. 

96 

120 

<< 

96 

110 

<( 

Saliva  increased. 

92 

105 

<< 

<  (             <  < 

96 

115 

96 

105 

<« 

Sweating. 

92 

110 

92 

105 

(( 

Arteries  much  contracted 

92 

110 

92 

110 

7:20 


Landed  at  Cherbourg. 


Protocol  16b.— On  "B,"  aboard  a  train.    July,  1909. 


a.m. 

9:22 

92 
96 

125 
125 

Sitting 

•  in  train  before  starting. 

9:25 

88 

125 

9:26 

88 
88 
92 

120 

95 

120 

On  moving  train. 

9:29 

88 

110 

9:30 

88 

115 

At  a  stop. 

9:31 

88 

105 

On  rapidly  moving  train. 

9:32 

88 

105 

9:33 

88 
88 

115 
120 

At  a  stop.    Arteries  ver: 

9:35 

88 

120 

9:36 

88 
84 
80 

115 
120 
120 

At  a  stop. 

9:40 

80 

120 

(< 

9:41 

80 

125 

Lying. 

At  a  stop. 

9:42 

68 

125 

Protocol  17.— On  "B,"  after  dressing  ashore.    July.  19,  1909, 


6:07 

84 

105 

Standing  after  dressing  ashore 

80 

105 

Feels  well. 

80 

105 

"        Arteries  small. 

6:12 

80 

105 

<  < 

6:13 

68 

125 

Lying.    Arteries  larger. 

464 


SEASICKNESS 


Time,    Pulse-  Blood- 
a.m.       rate,     press. 


68 

68 

6:16  64 

6 :  17  76 

80 

80 

6:20  84 


125 
125 
125 
115 
115 
120 
115 


Remarks. 


Lying. 


standing. 


7:15 
7:30 


7:41 
7:42 


7:45 
7:46 


7:49 
7:50 


8:15 
8:16 


8:24     88 


8:32 
8:33 


8:41 
8:42 


84 
88 
88 
88 
88 
88 
80 
72 
72 
72 
88 


00 
06 


88 
84 
88 
92 
84 
84 
84 
96 
96 
88 
88 
88 
84 
88 
84 
80 


105 
115 
130 
130 
130 
130 
135 
140 
135 
140 
125 
130 
125 
125 


130 
125 
130 
120 
135 
135 
135 
135 
135 
135 
140 
130 
130 
130 
130 
130 
130 
135 


July  20,  1909. 

Cup  of  tea. 

Standing  after  dressing  ashore. 
Arteries  contracted. 


Lying.     Arteries  larger  than  when  standing. 


Standing.    Arteries  contracted. 


Boarded    steamship  Cygne  bound  for  Gorey, 

Island   of  Jersey,   Channel  Islands,  from 

Carteret,  Manche. 
Boat  started. 
Ewald  breakfast.    Absorption  test  reacted 

in  15  minutes.     Motility  test  reacted  in  1 

hour  20  minutes. 
Sitting.      On  deck  in  hot  sun. 

Boat  rolling  and  pitching. 
Lump-sensation  in  stomach. 

Arteries  contracted. 

In  the  sun. 

Much  balancing  effort. 

Ship  rolling  and  pitching. 

Feels  well  in  spite  of  heat. 

Strong  odour  from  cook's  galley. 

On  deck  as  before. 

Arteries  moderately  contracted. 

Slight  lump-sensation  in  stomach. 

Eructations. 

On  deck  in  sun. 
Slight  headache. 


SEASICKNESS 


465 


Time,    Pulse-  Blood- 
a.m.      rate,    press. 


9:10     84 
9:38    84 


9:43     92 
9 :  45     . . 


Remarks. 


80      140      Sitting.    Otherwise  feels  well. 
88      140 


140 
135 


92  135 

96  120 

96  120 

92  125 


120 


On  deck. 

Arteries  moderately  contracted. 


Landed  at  Gorey. 


Protocol  18 — On  "B,"  aboard  the  fishing  smack  "duatre 
Freres."    July  22,  1909. 


A.in. 

8:53 

8:54 

9:00 


12:27 
12:28 


76      120 


80 

80 

9:22    76 

76 

76 
72 
72 
72 

72 
72 
72 
76 
9:59  72 
10:18     72 

12:00  .. 

p.m. 

12:24  80 
84 
84 
80 
76 
84 
76 
80 
76 
72 
76 

12:33  76 


125 
115 
105 
105 

115 
115 
125 
125 

115 
115 
90 
115 
115 
120 


130 
120 
120 
115 
115 
120 
130 
135 
135 
135 
135 
135 


Boat  started,  a  fresh  breeze  filling  her  sails. 
Lying  in  cabin.    Feels  sick.    Arteries  small. 

Odour  horrible. 

Boat  pitching  badly.    Sweating. 

Rapidly  getting  sicker. 

Arteries  not  so  small  now. 

Sweating.  Lump-sensation.  Saliva 
free. 

Lump  in  throat.    Wretched  all  over. 

Bathed  in  cold  sweat. 

Marked  lump-sensation  in  stomach. 

On  verge  of  vomiting.  Pain  in  epi- 
gastrium. 

Feels  better  now. 

Arteries  small.     Face  pale. 

On  verge  of  vomiting  again. 

Feels  better.     Sweating. 

*'      Arteries    small.      Feels    thoroughly 
wretched. 
The  rough  weather  compelled  the  crew  to  put 
back  into  the  harbour.    Put  ashore. 

Sitting  after  leaving  boat. 
Arteries  contracted. 


Lying.    Arteries  moderately  contracted. 


466 


SEASICKNESS 


Time, 

Pulse-  Blood- 

Remarks. 

p.m. 

rate. 

press. 

4:55 

92 

125 

Standing. 

Muscles  of  forearm  twitching. 

92 

120 

Arteries  moderately  large. 

96 

120 

Feels  nervous  and  irritable. 

92 

120 

Lump-sensation  still  in  stomach. 

96 

120 

5:02 

92 

120 

5:03 

76 

125 

Lying.     S 

ize  of  arteries  varies  slightly  from 
time  to  time. 

68 

135 

"          Pupils  normal. 

72 

130 

"         No  special  fulness  in  head. 

68 

130 

76 

125 

5:11 

72 

130 

5:12 

92 

105 

Standing. 

Arteries  moderately  contracted 
at  times,  and  at  other  times 
small. 

96 

105 

Standing. 

92 

135 

92 

135 

Lump-sensation  still  in  stomach. 

92 

130 

92 

120 

92 

135 

92 

125 

5:20 

88 

130 

The  subject  suffered  the  whole   afternoon 
from  the  effects  of  the  sea  trip. 

Protocol  19.— On  "B,"  aboard  the  "  Southwestern,"  from 
Cherbourg  to  Southampton.    July  23,  1909. 

Standing  in  cabin. 

"         Arteries  moderately  contracted. 

4  i 
** 

Lying.    Arteries  moderately  large. 


p 

m. 

11 

25 

80 

120 

80 

130 

80 

125 

30 

80 

125 

31 

72 

135 

68 

140 

68 

135 

36 

68 

135 

37 

76 

130 

80 

120 

80 

115 

:40 

84 

115 

.47 

, , 

^  , 

Standing.    Arteries  contracted. 


both    hypoder- 


12:04 
1:43 


76      125 


Strychnin  nitrate,  gr  1/40. 
Atropin   sulphate,  gr   1/75, 
mically. 

July  24, 1909. 

Boat  started. 

Lying.    Arteries  moderately  contracted. 


SEASICKNESS 


467. 


Time,    Pulse-    Blood- 
a.m.       rate,      press. 


1:46 


80 

72 
80 


135 
130 
135 


7:49     76      135 


Remarke. 


Lying. 


Following  an  Ewald  meal  given  at  12 :  34 
A.M.,  the  absorption  test  reacted  in  11 
minutes.  The  motility  test  did  not  react 
within  the  hour. 

The  blood-pressures  could  not  be  taken  with 
the  subject  standing  on  account  of  the  ex- 
cessive incessant  pitching  and  tossing  of 
the  boat. 

Standing  as  boat  approaches  pier  at  South- 
ampton. 


7:50 

84 

120   St 

anc 

88 

125 

84 

125 

84 

125 

88 

125 

88 

125 

84 

120 

84 

120 

84 

125 

84 

125 

8:11 

84 

120 

8:12 

72 

135   Ly 

ini 

76 

130 

76 

130 

72 

125 

72 

130 

8:18 

72 

130 

8:19 

80 

130   St 

anc 

84 

130 

<  < 

84 

125 

( < 

8:23 

84 

130 

<  < 

Jiily  28,  1909. 

Standing.     After  good  night's  rest  in  cool 
room. 
Arteries  moderately  contracted. 


Lying.    Arteries  moderately  contracted. 


Standing.     Arteries  much  contracted. 


In  an  Ewald  breakfast  given  at  7: 18  a.m.,  the  ab- 
sorption test  reacted  in  21  minutes.  The  motility  test 
did  not  react  within  the  hour. 


Protocol  20.— On  "  B,"  aboard  the  "Teutonic"  from  South- 
ampton to  New  York.    First  day  out.    July  28,  1909. 


a.m. 

U :  52  88 
88 
92 


110 
105 

no 


Standing  in  cabin. 


468 


SEASICKNESS 


Time, 

Pulse-  Blood- 

Remarks. 

a.m. 

rate. 

press. 

92 

110 

Standing  in  cabin. 

88 

115 

<  < 

. 

96 

120 

*i 

88 

110 

<< 

p.m. 

12:04 

88 

110 

<« 

12:05 

80 

135 

Lying. 

Arteries  moderately  large. 

80 

130 

< « 

76 

125 

(< 

76 

125 

i( 

76 

125 

<  < 

12:13 

80 

120 

<< 

12:14 

100 

120 

Standing.    Arteries  moderately  contracted. 

92 

115 

<< 

92 

110 

<  ( 

12:17 

88 

105 

<< 

Boat  sailed  from  Southampton 
at  12:15  P.M. 

5:05 

80 

140 

Standing.    Arteries  small. 

88 

135 

84 

135 

84 

135 

76 

135 

80 

135 

84 

130 

5:17 

84 

135 

( < 

5:18 

68 

145 

Lying. 

Arteries  moderately  contracted. 

72 

140 

<  < 

Fulness  in  ears. 

72 

145 

<  < 

68 

145 

<  ( 

68 

140 

<  < 

5:25 

68 

145 

<  < 

5:26 

76 

135 

Standing.    Arteries  contracted. 

80 

130 

<  < 

Room  cool. 

80 

135 

<  < 

76 

130 

<i 

80 

135 

«4 

5:31 

80 

130 

<< 

7:12 

84 

150 

<« 

After  dinner. 

80 

145 

<< 

84 

135 

«< 

88 

130 

<  < 

84 

140 

<  < 

84 

120 

<  < 

88 

125 

<  < 

7:26 

84 

115 

<  < 

7:27 

72 

140 

Lying. 

Arteries  moderately  large. 

72 

140 

<  < 

Slight  fulness  in  head. 

72 

140 

<  < 

Feels  well. 

68 

140 

<  < 

72 

140 

<< 

SEASICKNESS 


469 


Time, 

Pulse- 

Blood 

p.m. 

rate. 

press. 

80 

135 

76 

140 

7:36 

80 

135 

7:37 

92 

115 

84 

120 

84 

130 

84 

105 

84 

125 

84 

120 

84 

115 

84 

110 

88 

115 

88 

130 

84 

110 

7:55 

84 

110 

11:56 

80 

120 

80 

125 

76 

120 

a.m. 

12:01 

80 

120 

12:02 

72 

130 

68 

130 

68 

130 

12:05 

72 

130 

Protocol  21.— 0] 

a.m. 

7:48 

68 

120 

76 

125 

68 

125 

68 

115 

72 

120 

8:04 

72 

120 

8:05 

88 

120 

80 

115 

88 

115 

88 

120 

84 

115 

84 

110 

p.m. 

1:33 

76 

110 

72 

m 

Remarks. 


Lying. 


Standing. 


Some  balancing  efforts. 
Arteries    variable.      At     times 

small,    at   others   moderately 

large. 


Feels  well. 

Arteries  moderately  contracted. 


Lying  in  bed.    Arteries  slightly  larger. 


Feels  well.    Boat  moved  steadily  so 
far.    Weather  fair. 


On  "  B,"  aboard  "  Teutonic." 
July  29,  1909. 


Second  day  out. 


Lying  in  bed  after  awaking. 
Slept  fairly  well. 
Arteries  moderately  large. 


Standing.    Arteries  moderately  small. 
"  Ship  moving  steadily. 


*'  After     lying    some    hours    in 

Queenstown  harbour  the  boat  started  for 
New  York  at  1 :  10  p.m. 

Standing,    Arteries  contracted. 
C^bincold, 


470 


SEASICKNESS 


Time,    Pulse-  Blood- 
p.m.       rate,    press. 


80 

1:35  80 

1 :  36  68 

68 

72 

68 

1 :  43  80 

1:44  76 


76 
76 
72 
72 
80 
84 


1:51 
6:53 


6:59 
7:00 


7:06 
7:07 


7:12 
10:06 


10:12 
10:13 


10:19 


84 
88 
84 
72 
72 
72 
72 
68 
88 
88 
84 
84 
84 
72 
76 
76 
76 
76 
76 
68 
68 
68 
68 
64 
68 
68 


110 
110 
115 
120 
120 
115 
110 
110 

105 
110 
115 
115 
115 
115 

110 
110 
105 
130 
130 
130 
130 
130 
110 
100 
100 
100 
105 
105 
110 
110 
110 
105 
105 
120 
120 
120 
120 
120 
115 
115 


Remarks. 

Standing.     Does  not  feel  so  well. 

<  < 

Lying.     Arteries  considerably  contracted. 
"  Feels  chilly  and  not  so  well. 


Standing.     Arteries  vary  from   moderately 
small  to  moderately  large. 


Arteries  vary,  being  in  general 
moderately  large. 


Lying.     Arteries  moderately  large. 


Standing.     Arteries  vary  considerably. 


Ship  pitching. 
Arteries  vary. 
Arteries  small. 


Lying  in  bed.    Arteries  moderately  large. 


Protocol  22.— On  "  B,"  aboard  "  Teutonic."    Third  day  out. 


7:15 


72 
72 
72 


115 
115 
115 


July  30,  1909. 

Lying  in  bed  after  awaking. 

Arteries  moderately  contracted. 


SEASICKNESS 


471 


Time, 

Pulse-  Blood- 

a.m. 

rate. 

press. 

72 

115 

72 

115 

7:23 

72 

115 

7:24 

76 

115 

84 

115 

76 

125 

84 

120 

84 

115 

7:29 

84 

115 

8:10 

80 

115 

80 

110 

88 

115 

88 

115 

88 

110 

8:15 

88 

115 

p.m. 

3:30 

84 

125 

84 

115 

84 

110 

3:36 

88 

120 

3:37 

72 

130 

68 

125 

68 

130 

3:42 

72 

130 

3:43 

80 

115 

84 

110 

84 

110 

84 

105 

3:47 

88 

110 

5:00 

72 

130 

80 

120 

76 

130 

76 

130 

5:05 

76 

130 

9:54 

72 

120 

72 

115 

72 

115 

72 

115 

72 

115 

10:02 

72 

115 

10:03 

64 

115 

64 

115 

60 

115 

64 

110 

64 

120 

64 

110 

64 

120 

Remarks. 


Lying. 


Standing.     Some  balancing  efforts.     Rough 
weather. 
Ship  rolling  and  pitching  much. 


Condition  of  arteries  variable. 
Arteries  variable. 
Feels  well. 


Balancing  efforts. 

Ship  pitching  and  rolling  badly. 

Arteries  somewhat  contracted. 


Lying.     Arteries  large. 

"  Arterial  wall  quickly  recedes  from 

finger. 


Standing.     Arteries  moderately  contracted. 
Some  balancing  efforts. 
Ship  rolling  and  pitching. 

Cabin  warm. 
Much  balancing. 
Very  rough  seas. 


Arteries  moderately  contracted. 
Arteries  vary  slightly  from  time 
to  time. 


Lying  in  bed.     Arteries  moderately  large., 
Fulness  in  ears^ 
Face  flushed. 


472 


SEASICKNESS 


Time.    Pulse-  Blood- 
p.m.      rate,     press. 


10:15 


64 
68 


115 
115 


Remarks. 


Lying.     Ready  to  drop  into  sleep. 


Protocol  23.— On  "  B,"  aboard  "  Teutonic."    Fourth  day  out 

July  31,  1909. 

a.m. 

Lying  in  bed  after  awaking. 
"      Slight  occipital  headache  the  result 
of  studying  future  plans. 


Standing.    Cabin  warm. 

Arteries  variable. 
Sweating. 

Ship  steadier. 


Arteries  vary  within  moderate 
limits. 

Feels  well. 

Occasionally  slight  lump-sensa- 
tion in  stomach. 


7: 

19 

68 

120 

68 

120 

68 

120 

68 

120 

7: 

26 

68 

115 

88 

110 

92 

105 

88 

105 

92 

105 

7. 

34 

92 

105 

11: 

42 

88 

105 

76 

115 

. 

80 

115 

76 

115 

76 

110 

76 

115 

72 

115 

72 

120 

72 

115 

11 

:53 

76 

120 

p 

m. 

5 

14 

76 

125 

72 

125 

72 

125 

72 

125 

72 

130 

72 

125 

5 

24 

68 

125 

5 

25 

100 

115 

92 

115 

96 

110 

92 

110 

88 

115 

88 

105 

88 

110 

5 

35 

88 

105 

10 

42 

72 

115 

Lying  in  bed  after  sleeping. 
' '      Arteries  moderately  contracted  though 
slightly  variable. 


Standing.    Arteries  variable. 


76      116 


Cabin  warm. 
Ship  very  steady. 


Arteries  variable,  but  in  general 
moderately  large. 


SEASICKNESS 


473 


Time,    ] 

Pulse-  Blood- 

Remarks. 

p.m. 

rate. 

press. 

96 

105 

Standing. 

92 

110 

88 

115 

Ship  steady. 

84 

115 

76 

110 

Port-holes  open. 

76 

110 

80 

110 

10:54 

76 

110 

10:55 

64 

64 
64 
64 
64 

120 

120 
120 
120 
120 

Lying   in 

bed.     Arteries   moderately   con- 
tracted. 

11:02 

64 

120 

Protocol  24.— On  "  B,"  aboard  "  Teutonic."    Fifth  day  out. 

August  1,  1909. 

a.m. 

7:32 

64 
68 
68 
72 
68 

115 
120 
125 
125 
125 

Lying  in 

<< 
(( 

bed  after  awaking. 

7:42 

68 

120 

<( 

7:43 

88 

100 

Standing 

.    Feels  well. 

88 

105 

4  < 

Cabin  oppressively  hot. 

92 

100 

<( 

Sweating. 

92 

105 

(( 

92 

100 

«( 

7:50 

92 

100 

f  « 

8:30 

92 

100 

(< 

After  dressing. 

92 

105 

<< 

No  lump-sensation. 

88 

100 

•  • 

92 

100 

l( 

Ship  steady. 

92 

100 

4< 

Arteries  large. 

92 

100 

(( 

96 

100 

•  < 

Weather  very  warm. 

8:39 

96 

100 

(4 

p.m. 

1:30 

84 

100 

i< 

Arteries  variable. 

96 

100 

<< 

Blood-pressure   at  times    lower 
than  recorded. 

92 

100 

<« 

88 

105 

«« 

88 

100 

l« 

1:38 

92 

100 

<< 

1:39 

68 

135 

Lying. 

Arteries  large. 

474 


SEASICKNESS 


Time, 

Pulse- 

Blood- 

p.m. 

rate. 

press. 

72 

135 

68 

135 

1:43 

68 

145 

1:44 

88 

105 

88 

105 

88 

110 

1:47 

88 

105 

4:04 

72 

120 

76 

120 

76 

120 

4:08 

76 

115 

4:09 

64 

125 

64 

125 

68 

125 

4:15 

64 

120 

4:16 

72 

115 

80 

115 

72 

115 

4:20 

76 

115 

9:15 

88 

100 

84 

105 

84 

105 

84 

110 

84 

110 

84 

110 

84 

105 

9:23 

84 

100 

9:24 

68 

125 

68 

125 

68 

125 

9:29 

68 

125 

Remarks. 


Lying. 


standing.    Arteries  vary  moderately. 


After  being  on  deck  in  cool  air. 


Lying.    Arteries  moderately  large. 


Standing.    Arteries  vary  slightly. 


In  hot  cabin. 

Arteries  variable   but  for  the 
most  part  dilated. 


Lying  in  bed.    Arteries  moderately  large. 


Protocol  25.— On  "B,"  aboard  "Teutonic."    Sixth  day  out. 

August  2,  1909. 


Lying  in  bed  after  awaking. 
"      Had  a  fair  night,  but  the  cabin  was 
fearfully  hot. 


"      Weather  very  warm. 

Standing.    Arteries  variable,  but  in  general 
moderately  large. 


a.m. 

7:33 

64 

115 

68 

115 

72 

120 

68 

115 

68 

115 

7:40 

68 

115 

7:41 

96 

100 

96 

105 

92 

105 

92 

100 

SEASICKNESS 


475 


Time, 

Pulse-  Blood- 

Remarks. 

a.in. 

rate. 

press. 

84 

100 

Standing.    Sweating. 

92 

100 

88 

100 

Temperature  of  air  in  cabin, 
90°  F. 

7:49 

92 

100 

11:36 

72 

120 

"           In  cool  cabin.    Port-hole  open. 

64 

130 

Feels  well. 

64 

125 

68 

125 

68 

130 

11:43 

64 

130 

11:44 

72 

120 

Lying.    Arteries  moderately  large. 

64 

125 

<  < 

64 

125 

<( 

64 

125 

<  < 

60 

120 

it 

11:52 

60 

120 

Standing.    Arteries  moderately  small. 

76 

120 

72 

120 

72 

125 

72 

120 

11:58 

72 

125 

p.m. 

1:05 

56 

130 

Lying  after  sleeping. 

60 

125 

<  < 

64 

125 

"      Arteries  moderately  contracted. 

64 

125 

<( 

64 

125 

(( 

1:11 

60 

125 

( ( 

1:12 

72 

130 

Standing.  Arteries  vary,  but  in  general 
are  contracted. 

72 

130 

68 

125 

72 

130 

68 

130 

1:17 

68 

135 

9:38 

72 

110 

**            Arteries  moderately  large. 

72 

115 

72 

115 

**  Temperature  of  air  in  cabin, 
68°  F. 

76 

115 

72 

115 

9:45 

76 

115 

9:46 

68 

120 

Lying  in  bed.    Arteries  moderately  large. 

68 

125 

<  < 

64 

125 

( ( 

64 

125 

<i 

64 

125 

(< 

64 

120 

(( 

9:53 

60 

120 

(« 

476 


SEASICKNESS 


Protocol  26.— On  "  B,"  aboard  "  Teutonic.*'    Seventh  day  out. 

August  3,  1909. 


Remarks. 

Lying  in  bed  after  awaking. 

Slight  headache  from  thinking  over 
future  plans. 


Standing.    Arteries  variable. 

"  Temperature    of    air  in  cabin» 

74°  F. 


Time, 

Pulse-  Blood 

a.m. 

rate. 

press. 

7:37 

64 

125 

64 

125 

64 

125 

68 

125 

64 

120 

7:46 

64 

120 

7:47 

80 

110 

84 

110 

84 

110 

80 

100 

80 

100 

80 

100 

80 

110 

84 

115 

88 

115 

7:56 

88 

115 

p.m. 

5:40 

84 

110 

80 

115 

80 

115 

5:43 

80 

110 

5:44 

68 

130 

68 

135 

64 

130 

5:47 

64 

125 

5:48 

76 

115 

80 

115 

84 

110 

5:52 

80 

110 

11:36 

72 

120 

72 

120 

72 

115 

11:40 

72 

115 

11:41 

64 

120 

64 

125 

64 

125 

11:45 

64 

125 

Lying. 


Arteries  variable. 

Sweating. 

Temperature  of    air  in    cabin, 
81°  F. 

Cabin  stuffy. 
Arteries  moderately  large. 
Tired  after  walking  on  deck. 


Standing.    Arteries  variable. 


Arteries  moderately  contracted. 


Lying  in  bed.     Arteries  moderately  con- 
tracted. 
"       Delightful  cool  night. 


August  4,  1909.    Eighth  day  out  on  "Teutonic." 


a.m. 


7 :  52    64      115      Lying  in  bed  after  awaking. 

68      120         "      Arteries  moderately  contracted 


SEASICKNESS  477 

Time.     Pulse- Blood-  Remarks. 

a.m.       rate,    press. 

68  120      Lying.     Temperature  of  air  in  cabin,  69°  F. 

7:56     72  120 

7 :  57     92  105      Standing.     Arteries  moderately  contracted. 

84  110 

88  115 

8:01  84  115 

August  5,  1909.    Boat  lying  in  New  York  Harbour. 


a.m. 


5:41 

68 

120 

68 

120 

68 

120 

5:46 

68 

120 

5:47 

88 

115 

88 

115 

88 

115 

5:50 

88 

115 

8:00 

,  , 

,  , 

Lying  in  bed  after  awaking. 


Standing  in  stuffy  cabin. 

Temperature  in  cabin,  71°  F. 
(( 

"         Arteries  moderately  contracted. 
Landed  in  New  York. 


CHAPTER  XXX 

HISTORY  AND   LITERATURE  OF   SEASICKNESS 

Judging  from  the  extent  of  its  literature,  seasickness 
has  been  a  much  discussed  question  in  the  past.  All  sorts 
of  theories  have  been  adduced  to  explain  the  causation  of 
its  phenomena.  Many  of  the  articles  written  by  the  older 
men  contain  ingenious  theories  backed  with  numerous 
clinical  facts  and  sustained  by  vigorous  argument. 

Hippocrates  alludes  to  the  perturbations  of  the  body 
caused  by  navigation.  Cicero  was  a  victim  and  it  was 
even  said  of  him  that  sooner  than  endure  the  seasickness 
he  suffered  on  the  vessel  in  which  he  had  taken  refuge 
from  Mark  Antony  he  gave  himself  up  to  his  executioners. 

Pliny  276  i^ag  a  good  word  for  some  drink  as  a  remedy  : 
"Nauseam  maris  arcet  in  navigationibus  potum.'^ 

Cato  229  the  Elder,  said  that  one  of  the  greatest  regrets 
of  his  life  was  that  he  had  made  a  journey  by  sea  that 
he  could  have  made  by  land.  Lord  Bacon  was  also  a 
sufferer  from  seasickness  and  carried  a  sachet  filled  with 
saffron  as  a  preventative. 

Many  other  names  holding  high  place  in  the  history  of 
science^  art,  and  letters,  might  be  mentioned  to  show  what 
little  regard  the  sea  has  for  the  condition  or  personality 
of  those  committed  to  its  tender  mercies. 

Erasmus  Danvin^^o  (1796)  attributes  the  vertigo  from 
circumgyration  (vertigo  rotatoria)  to  an  increase  of  the 
irritative  motions  of  vision  and  when  the  rotatory  motions 
are  continued  too  long  or  are  too  violent,  sickness  of  the 
stomach  follows.  To  a  similar  cause  he  attributes  the 
sickness  following  vinous  intoxication  and  the  motions  of 
a  ship.  Wollaston23i  (1810)  considers  the  inertia  of  the 
blood  to  be  the  cause  of  seasickness.  As  the  boat  de- 
iscends  a  pressure  equal  to  that  of  a  six  foot  column  of 
blood  is  taken  off  the  blood-vessels  so  that  they  contract 
and  cause  congestion  of  the  brain. 

478 


SEASICKNESS  479 

Jobert^^^  (1846)  cites  the  theories  of  his  time,  and 
attributes  seasickness  to  indigestion  caused  by  disturb- 
ances of  the  sympathetic  nervous  system. 

Pellarin233  (1851)  considers  the  cause  as  a  disturbance 
of  the  circulation,  the  symptoms  being  due  to  cerebral 
anaemia. 

Sewanas  ^^^  wrote  a  large  volume  in  which  he  contend- 
ed that  seasickness  was  due  to  a  miasmatic  poison  exist- 
ing in  the  atmosphere  over  the  sea.  The  miasma  origi- 
nated in  the  decomposition  of  organic  detritus  in  the  sea, 
and  was  therefore  more  abundantly  manifest  when  the  sea 
was  agitated. 

Guillabert  235  (1859)  accepted  the  theory  of  Sewanas 
as  demonstrated. 

Berard^ss  (1850)  attributes  the  vomiting  of  seasick- 
ness to  disturbance  of  the  central  nervous  system. 

Nelken  ^^^  (^  1856)  observes  that  few  persons  are  immune. 
Children  under  2  years  are  exempt,  but  children  from  2 
to  7  years  are  more  liable,  whilst  after  7  the  susceptibil- 
ity is  the  same  as  in  adults.  He  states  that  dogs,  sheep, 
cows  and  chickens  are  subject  to  the  malady,  whilst  hogs, 
ducks  and  geese  are  unaffected.  His  view  is  that  the 
motions  of  the  ship  are  communicated  to  the  various 
viscera  within  the  abdomen,  thorax,  cranium  and  spinal 
canal,  and  that  according  to  the  idiosyncrasy  of  each  in- 
dividual various  symptoms  manifest  themselves. 

Chapman  ^^s  (1864)  considered  spinal  congestion  as  the 
cause  of  seasickness,  and  strongly  recommended  a  speci- 
ally constructed  ice-bag  applied  to  the  whole  length  of  the 
spine.  Many  good  results  were  reported.  The  travellers 
were  instructed  however  to  lie  flat  upon  the  ice-bag,  i.e., 
in  dorsal  decubitus. 

Barker  239  (1870)  considers  seasickness  as  due  to  the 
sudden  and  recurring  changes  of  the  relations  of  the  fluids 
to  the  solids  of  the  body,  and  to  the  nervous  disturbances 
which  result  from  these  changes. 

Pollard  240  (1872)  attributes  seasickness  to  the  con- 
sciousness of  a  want  of  support  in  the  downward  move- 
ments of  the  ship,  causing  thereby  strong  psychic  irrita- 
tion. 

Guien24i  (1876)  divides  the  causes  into  those  which 
affect  the  nervous  system  as  a  whole,  such  as  the  motions 


480  SEASICKNESS 

of  the  boat,  and  those  which  affect  pai-ticular  nerves  as 
bad  odours,  noises,  etc. 

Beard  242  (1881)  attributes  seasickness  to  a  series  of 
concussions.  He  denies  that  the  symptoms  of  seasickness 
are  "reflexed  through  the  eyes."  Infancy  and  old  age 
escape;  neurotic  individuals  are  more  susceptible. 

Kramer  243  (1892)  studied  the  fundus  oculi  in  seasick- 
ness, and  found  in  most  of  the  cases  the  "vessels  thin  and 
narrow  and  the  chorioid  of  a  pallor  otherwise  found  after 
protracted  hemorrhages."  He  considers  cerebral  anemia 
as  the  cause  of  seasickness,  the  psychic  element  being  an 
important  factor.  The  cause  of  the  cerebral  anaemia  he 
leaves  an  open  question. 

D'Ailhaud  Castelet^^^  (1895)  attributes  seasickness  to 
abnormal  excitement  of  the  sensory  nerves  of  the  skin  and 
viscera  and  to  irritations  of  the  vagus,  sympathetic,  sense 
organs,  muscular  sense  and  of  the  sense  of  space  which 
induces  peripheral  vaso-constriction  with  compensatory 
visceral  vaso-dilatation,  hypnosthenia  of  the  heart  muscle, 
lowered  blood-pressure,  cerebral  anaemia  and  miosis. 

Tousey  ^^s  (1896)  considers  most  cases  of  seasickness 
as  due  to  reflex  causes  from  the  visual  apparatus  or  from 
the  semicircular  canals.  Few  cases  are  caused  by  succus- 
sion  of  the  stomach. 

Rosenbach  ^46  (1896)  repudiates  fear,  abnormal  visual 
impressions,  deficient  function  of  the  kidneys  or  lungs 
and  miasmastic  poisoning,  as  being  at  best  merely  associ- 
ated factors  and  not  the  cause  of  seasickness.  The  move- 
ments of  the  ship  are  the  all-important  factor  and  of  these 
the  screw  or  spiral  motion  is  the  most  effective.  The 
stamping  or  pitching  motion  is  next  in  effect,  whilst  the 
rolling  motion  is  the  least  effective  of  all.  He  also  states 
that  it  is  at  the  "end  of  the  upward  motion"  and  the  "be- 
ginning of  the  rise"  that  the  greatest  influence  is  exerted, 
i.e.,  when  the  direction  of  the  motions  is  reversed.  All 
authors,  he  says,  agree  on  this  point.  These  movements 
according  to  Rosenbach  affect  the  body  by  causing  intra- 
and  inter-molecular  disturbances  of  dynamic  equilibrium 
within  the  organism.  He  believes  that  vomiting  is  due 
tf)  a  definite  mechanical  influence  upon  the  organic  tissue 
of  the  stomach.  The  vomiting  is  a  functional  interference 
without  the  primary  intervention  of  a  nerve  influence. 


SEASICKNESS  481 

Hazen247  (1904)  attributes  seasickness  to  a  deficiency 
in  innervation  of  the  extrinsic  muscles  of  the  eye.  On  a 
vessel  we  have  the  severest  test  for  ' '  immunity  of  the  pan- 
oramic symptom."  The  condition  for  prevention  of  sea- 
sickness is  to  have  the  standard  strength  of  these  muscles. 

Klein  248  (1897)  attributes  seasickness  to  the  effect 
of  pressure,  traction  and  concussion  upon  the  nervous 
elements  in  the  movable  organs. 

DeVries  (1899)  considers  seasickness  as  a  functional 
disease  of  the  nerv^ous  system,  caused  by  repeated 
mechanical  agitation  of  the  body. 

DarnalP^o  (1899)  concludes  that  seasickness  results 
from  a  disturbance  of  equilibration  caused  by  disturbance 
of  the  endolymph  in  the  semicircular  canals.  He  makes 
no  attempt  to  explain  the  modus  operandi. 

Sumner  251  (1900)  relates  the  story  of  a  house  which 
had  been  carried  away  in  a  flood,  and  on  the  subsidence 
of  the  waters  left  in  a  tilted  position,  partly  in  the  water 
and  partly  on  dry  land.  No  part  of  the  house  floated  or 
moved.  Every  one  who  entered  this  house  experienced 
feelings  like  those  of  seasickness,  and  some  even  vomited. 
He  considers  seasickness  as  due  to  a  "flood  of  conflicting 
impressions  conveyed  to  the  mind  through  vision, ' '  and, 
therefore,  as  purely  a  psychic  disturbance. 

Schwerdt252  (190I)  attributes  seasickness  to  circulat- 
ory disturbances,  with  disordered  equilibrium  as  a  cause 
of  secondary  importance.  He  bases  his  conclusions  upon 
manometric  measurements  of  intra-abdominal  pressure, 
registered  by  "an  ordinary  manometer  which  was  alter- 
nately connected  with  the  stomach  and  the  bowel  (rec- 
tum) by  suitable  insertions."  Although  it  is  now  known 
that  such  measurements  of  pressure,  taken  within  the  hol- 
low viscera,  by  no  means  represent  intra-abdominal  pres- 
sure, yet  the  author  repeated  Schwerdt's  experiments  and 
found  no  such  constancy  in  the  phenomena  as  reported. 
Great  credit  is,  nevertheless,  due  to  Schwerdt  as  being 
one  of  the  first  to  approach  the  study  of  seasickness  in 
accordance  with  the  scientific  spirit  of  the  times.  It  is 
a  relief  to  find  some  one  in  the  literature  checking  the 
monotony  of  a  mere  expression  of  views  by  appeal  to 
experimental  fact. 

Savor}^253  (1901)  considers  the  cause  as  purely  reflex 


482  SEASICKNESS 

and  physiological,  acting  primarily  through  the  semi- 
circular canals.  He  considers  the  connection  between  the 
upper  division  of  the  auditory  nerve  and  the  geniculate 
ganglion,  and  between  the  latter  and  the  vagus,  as  form- 
ing a  complete  chain  from  the  auditory  to  the  pneumo- 
gastric  terminals.  Savory  .is  the  only  one  so  far  who 
has  made  any  attempt  to  trace  the  paths  of  nerve  im- 
pulses, or  to  commit  himself  fearlessly  to  an  open  dec- 
laration of  his  views.  It  is  now  known  that  no  pathway 
exists  between  the  vagus  and  the  eighth  nerves  within  the 
ear.  Savory  is  entitled  to  credit  for  having  made  the 
first  attempt  at  a  rational  explanation  of  the  phenomena 
of  seasickness. 

Weitlauer  249  (1903)  after  numerous  observations  and 
measurements,  concludes  that  seasickness  is  due  to  trau- 
matism originating  in  repeated  differences  in  pressure  of 
the  fluid  and  soft  elements  of  the  body,  as  compared  with 
the  solid  elements. 

Cornelius  255  (1903)  seeks  the  cause  of  seasickness  in 
a  combination  of  Rosenbach's  kinetic  theory  with  his 
own  pressure-point  theory,  the  nerve  points  being  irri- 
tated by  the  disturbances  of  equilibrium,  thereby  sending 
stimulating  impulses  to  the  centre. 

Binz^^  (1903-4)  considers  seasickness  as  due  to  cere- 
bral anajmia  caused  by  stimulation  (from  the  rocking 
motions)  of  the  vaso-motors  of  the  brain.  He,  however, 
admits  the  possible  connection  between  cerebral  ischicmia 
and  involvement  of  the  organs  of  equilibration.  Binz 
used  Kreidl's  onychoscope,  an  instrument  which  registers 
on  a  dial  plate  the  rate  and  strength  of  the  pulse  in  a  nail 
segment,  in  his  investigations,  and  found  that  under 
rhythmical  lowering  and  raising  of  the  arm,  the  vessels 
became  filled  in  a  notably  slower  manner  than  they  emp- 
tied themselves.  The  plethora  is  j)ermanently  overcom- 
pensated  by  a  relative  ischaemia  during  the  vibrations. 

Pfanz''^  (1903),  from  his  observations  with  the  aid  of 
Kreidl's  onychoscope,  Basche's  sphygmomanometer,  and 
Gaertner's  tonometer,  held  it  as  probable  that  an  alter- 
nate inflow  and  outflow  oi  the  })lood  in  the  brain  induced 
by  the  rocking  motions  of  the  boat  which  raise  and  lower 
the  head,  causes  cerebral  stimulation,  which  in  turn  is 
responsible  for  the  retching  and  vomiting  of  seasickness. 


SEASICKNESS  483 

He  also  observed  an  increase  in  blood-pressure  at  the 
same  time.  Both  Binz  and  Pfanz  are  entitled  to  credit 
for  applying  experimental  methods  to  the  study  of  sea- 
sickness. 

Hagen-Torn  ^''^  (1903)  considers  seasickness  as  due  to 
cerebral  anaemia,  caused  by  reflex  contraction  of  the  cere- 
bral vessels.  "The  impossibility  of  adaptation  to  the 
constantly  changing  relations  of  the  body  toward  its  sur- 
roundings" is  the  primary  cause  of  the  phenomena. 

Koepke^s^  (1904)  believes  that  seasickness  is  due  to 
cerebral  ansemia. 

Waugh^^o  (1904)  considers  the  cause  of  seasickness 
to  be  a  paralysis  of  the  vaso-motor  nerves  with  accumu- 
lation of  blood  in  the  viscera  (abdominal)  and  anaemia 
elsewhere,  especially  in  the  brain. 

Shelmerdine -^^  (1904)  insists  that  a  predisposition  is 
necessary  in  order  that  the  ship's  motion  may  cause 
nausea.  Seasickness  results  from  a  combination  of  three 
factors,  viz. :  (1)  mechanical,  i.e.,  overwork  of  the  mus- 
cles in  balancing;  (2)  mental;  and  (3)  irritation  from 
the  presence  of  bile  in  the  stomach. 

Corning  2^-  (1904),  by  means  of  a  revolving  chair  in- 
duced vertigo,  nausea,  and  cardiac  weakness.  Then  he 
experimented  with  variouf=  drugs  with  a  view  to  finding 
a  remedy  which  would  hole  the  phenomena  in  abeyance. 
He  found  a  combination  of  hyoscin  and  morphin  to  be 
the  most  effective.  Observing  the  similarity  between  the 
phenomena  of  rotation  sickness  and  those  of  seasickness 
he  next  proceeded  to  treat  seasickness  in  the  light  of  his 
findings.  On  a  voyage  he  himself  took  hyoscin  hydro- 
bromid,  gr  1/50;  opium,  gr  ss;  and  ten  minutes  later  re- 
sorcin,  gr  iii,  with  nitroglycerin,  gr  1/300.  The  result 
was  wonderful.  He  seemed  to  be  in  such  a  state  that  he 
could  not  be  made  sick,  and  went  to  the  bow  of  the  ship 
in  defiance  of  the  elements.  He  treated  twenty  other 
passengers,  to  whom  he  gave  a  combination  of  morphin, 
atropin,  cocain,  and  resorcin,  and  found  that  "thus 
torpid  at  centre  and  periphery,  the  subject  usually  re- 
mained proof  against  giddiness  and  nausea  for  from  four 
to  seven  hours."  A  tablet  was  then  given  containing 
morphin,  gr  1/6;  nitroglycerin,  gr  1/300;  strychnin  sul- 
phate,  gr  1/60;  resorcin,  gr  i;    cocain  hydi'ochlorid,   gr 


484  SEASICKNESS 

1/6.  This  was  sufficient  to  procure  further  immunity  for  a 
like  period.  Most  of  his  subjects,  however,  preferred  to 
lie  down  after  taking  the  drugs.  Corning  does  not  at- 
tempt to  explain  the  causation  of  the  phenomena  of  rota- 
tion sickness  or  of  seasickness.  He  deserves  credit  for 
making  a  practical  attempt  to  find  a  remedy  for  seasick- 
ness by  invoking  the  aid  of  experimental  methods  and 
applying  the  results  of  his  findings  to  practice. 

Thoma263  (1904)  attributes  seasickness  to  a  "defi- 
cient sense  of  equilibrium, ' '  this  faculty  being  imperfectly 
developed  in  the  majority  of  individuals.  He  states  that 
seasickness  is  never  observed'  among  birds,  in  which  the 
organ  of  equilibrium  is  most  highly  developed,  and  acro- 
bats. Children  or  infants,  and  those  suffering  from 
incurable  disease,  are  usually  spared. 

Zingher264  (1905)  considers  the  etiology  of  seasick- 
ness as  still  obscure,  and  does  not  commit  himself  to  an 
opinion.  He  eulogizes  a  proprietary  preparation  in  the 
treatment  of  seasickness. 

Regnault  ^65  (1906)  distinguishes  between  psychic  and 
somatic  seasickness.  Bonnet,  Berillon,  Van  Renterghem, 
and  Farez  hold  similar  views. 

Roesen  (1907)  and  Simon  (1907)  evidently  consider 
cerebral  anaemia  to  be  the  cause  of  seasickness.  They 
employed  Bier's  method  of  congestion  for  the  relief  of 
the  condition.  Each  believes  he  saw  good  results  from 
this  method. 

Simon  ^^4  used  an  adjustable  elastic  necktie,  which 
was  applied  to  the  neck  for  half  an  hour  at  a  time. 

Flasschoen  284  (1907)  attributes  seasickness  to  a  dy- 
namic disturbance  at  the  base  of  the  brain,  and  especially 
in  the  optic  thalamus  and  corpora  striata.  He  adduces 
no  facts  or  reasons  for  his  assumption. 

Barnett^ss  (1907)  attributes  seasickness  to  irritation 
of  the  auditory  nerve  terminals  by  movements  of  the  en- 
dolymph  in  the  semicircular  canals.  This  irritation  is 
transmitted  to  the  vagus  through  the  facial.  Possibly, 
also,  the  irritation  is  transmitted  to  the  sympathetic  sys- 
tem through  the  external  petrosal  branch  of  the  genicu- 
late ganglion.  It  is  now  known  that  the  apparent  con- 
nection between  the  facial  and  auditory  nerves  (fila 
anastomica)  consists  merely  of  aberrant  strands  of  facial 


SEASICKNESS  485 

f 

fibres  that  return  to  the  facial  after  temporary  association 
with  the  auditory. 

Maillet257  (1908)  considers  seasickness  as  the  result 
of  reflexes  from  all  the  floating  organs. 

Van  Trostenburg  258  (1908)  considers  seasickness  as 
the  result  of  disorientation  in  space  associated  with  a 
series  of  interacting  disturbances  arising  from  unaccus- 
tomed optic,  kinsesthetic,  and  labyrinthine  irritations. 

Various  other  theories  have  been  advanced  from  time 
to  time,  most  of  which  fall  under  one  or  other  of  these 
heads,  as  given  by  Rosenbach : 

1.  The  localization  theory. 

2.  The  somatic  (mechanical)  theory,  which  includes: 
(a)  the  theory  of  circulatory  disturbances;  (b)  centrifu- 
gal force  theory;  (c)  the  cerebral  theory;  (d)  the  abdom- 
inal theory;   (e)  theory  of  the  static  centre. 

3.  The  theory  of  psychic  and  ocular  vertigo  (the  in- 
fluence of  will-power,  fear,  etc. ) . 

4.  The  theory  of  intra-  and  inter-molecular  disturb- 
ances ( Rosenbach 's  theory). 


•      CHAPTER  XXXI 

ETIOLOGY   OF   SEASICKNESS 

Of  the  various  theories  put  forward  to  account  for  the 
phenomena  of  seasickness  not  one  affords  a  reasonable 
explanation  that  is  applicable  to  any  large  number  of 
cases.  An  exception,  perhaps,  must  be  made  in  the  case 
of  those  theories  which  attribute  the  malady  to  disturb- 
ances of  the  endolymph  in  the  semicircular  canals  (Bar- 
nett,  Savory,  and  others).  Even  here  no  proof  has  been 
offered  to  show  that  such  disturbances  are  in  fact  the 
cause  of  seasickness;  and  with  the  exception  of  attempt- 
ing to  show  a  continuity  of  fibre-paths  (now  known  not 
to  exist)  between  the  auditory  nerve  and  the  pneumo- 
gastric  through  the  facial  (Savory,  Barnett),  no  effort  has 
been  made  to  explain  the  modus  operandi^  or  to  outline 
the  mechanisms  and  structures  involved. 

Before  attempting  to  establish  the  cause  of  seasick- 
ness, a  few  words  are  necessary  about  the  psychic  factor 
BO  often  mentioned  in  connection  with  the  malady.  In  a 
certain  limited  class  of  persons  the  psychic  element  is 
undoubtedly  of  importance.  Thus  in  a  previous  chapter 
it  was  stated  that  one  of  the  subjects  of  these  studies  be- 
came ill  from  merely  boarding  his  ship  on  the  eve  of 
commencing  a  journey.  All  the  indications  afforded  him 
good  reasons  for  believing  that  he  would  become  dread- 
fully seasick  on  the  voyage.  Here  was  a  case  where  evi- 
dently the  psychic  element  was  paramount.  Analysis, 
however,  shows  that  this  of  itself  is  not  sufficient  proof 
that  psychic  causes  alone  can  primarily  produce  the  phe- 
nomena of  seasickness.  On  this  occasion  the  underlying 
factors  were  subconscious  (latent)  memories  of  previous 
experiences,  which  themselves  were  the  direct  result  of 
genuine  seasickness  produced  in  the  usual  way.  More- 
over, in  this  instance  the  psychic  factor  had  the  support 

486 


SEASICKNESS  487 

of  powerful  associated  causes,  viz. ,  the  foul  odours  and  the 
dismal,  unsightly  aspect  of  affairs  between  decks.  As  we 
shall  see  later,  psychic,  like  circulatory  and  gastric  dis- 
turbances, are  always  associated  with  seasickness  to  a 
greater  or  less  extent;  and,  like  them,  may  be  potent, 
secondary  sources  of  discomfort.  This,  however,  does 
not  elevate  them  to  the  dignity  of  being  the  cause  of  sea- 
sickness in  the  strict  sense.  Many  individuals  of  the 
neurotic  type,  whom  one  would  expect  to  be  the  victims 
of  seasickness,  are  immune;  whilst,  on  the  other  hand, 
the  most  robust  individual,  with  every  indication  of  a 
well-balanced  nervous  system,  may  get  sick  eveiy  time 
he  goes  to  sea.  The  author  has  known  a  woman  of  re- 
markably neurotic  type  who  had  been  the  victim  of  sea- 
sickness all  her  life,  until  a  certain  age,  when  she  unex- 
pectedly began  to  develop  immunity.  Simultaneously 
with  her  immunity  there  developed  bilateral  nerve  deaf- 
ness, which  was  hereditary  in  her  family.  This  woman's 
sister  had  her  hearing  impaired  equally  in  both  ears  early 
in  life,  and  was  always  immune  to  seasickness,  although, 
judging  from  the  psychic  and  neurotic  standpoint,  every 
appearance  gave  indication  that  she  ought  to  be  a  victim. 
In  middle  life,  however,  owing  to  acute  disease,  she  be- 
came totally  deaf  in  one  ear;  and,  on  the  next  occasion 
of  her  going  to  sea,  she  discovered  that  she  had  devel- 
oped a  susceptibility  for  seasickness,  and  could  get  relief 
in  no  other  way  than  by  lying  upon  the  back  or  upon  the 
side  in  which  the  hearing  had  been  destroyed.  It  will  be 
remembered  that  the  sheep  and  dog,  with  unilateral  di- 
vision of  the  vestibular  nerve,  lay  upon  the  side  of  op- 
eration, because  in  any  other  position  they  experienced 
vertigo  and  developed  nystagmus.  The  immunity  of 
deaf  mutes  to  galvanism  over  the  mastoid  areas  and  to 
rotation-sickness  (James, ^^e  Kreidl,267  and  others),  and 
of  animals  in  which  both  labyrinths  have  been  removed 
(Ewald,277  Hog}"es278)^  or  both  vestibular  nerves  divided 
(Schiff  279)j  is  relevant  here. 

The  onset  of  mild  unilateral  inflammation  of  the  mid- 
dle ear,  or  even  the  unilateral  exacerbation  of  old  middle- 
ear  disease,  may  render  a  subject  who  had  been  previously 
immune  very  susceptible  to  seasickness  or  car-sickness. 
One  such  case  was  recently  studied.     The  patient  was  a 


488  SEASICKNESS 

woman  of  thirty-three,  whose  hearing  had  been  very  poor 
since  the  age  of  four,  when  she  had  had  severe  bilateral 
otitis  media  suppurativa,  complicating  scarlet  fever. 
This  patient  had  not  been  subject  to  sea-  or  car-sickness 
within  her  memory,  and  yet  she  was  of  a  distinctly  neu- 
rotic type.  In  her  fifth  month  of  pregnancy  she  went 
shopping  and  found,  to  her  dismay,  that  riding  in  the 
cars  not  only  made  her  weak,  dizzy,  and  nauseated,  but 
initiated  cramps,  which  strongly  stimulated  uterine  con- 
tractions. The  patient  had  no  fever,  but  showed,  upon 
examination,  distinct  evidence  in  the  left  ear  of  acute 
exacerbation  of  the  dormant  inflammatory  conditions 
existing  in  both  ears.  She  had  had  a  slight  pain  in  the 
left  ear  for  two  or  three  days.  With  this  pain  she  noticed 
that  her  hearing  for  high  notes  had  improved.  There  was 
some  tenderness  to  pressure  in  the  left  ear.  On  standing 
with  the  eyes  closed  the  patient  was  inclined  to  fall 
toward  the  right.  Turning  the  head  from  one  side  to  the 
other,  i.e.,  rotating  it  upon  the  long  axis  of  the  body, 
made  her  dizzy  and  sick.  With  the  eyes  turned  to  the 
left,  there  was  well-marked  horizontal  and  rotary  nystag- 
mus to  the  left  and  with  the  watch.  With  the  eyes 
turned  to  the  right  there  was  a  mere  trace  of  rotary  move- 
ment, which  was  slow  and  directed  against  the  watch.. 
With  the  eyes  directed  up  and  down  there  was  no  visible 
nystagmus.  The  knee-  and  wrist- jerks  were  equal  on 
either  side  of  the  body  and  somewhat  hyperactive.  The 
pupils  were  equal,  and  exhibited  the  usual  rhythmic  al- 
ternations of  short  range,  with  the  phase  of  dilatation  al- 
ways the  more  salient,  flurrying  or  moving  about  rapidly 
made  the  patient  weak  and  dizzy,  and  evoked  the  abdom- 
inal pains  referred  to.  At  times  the  sight  was  blurred 
and  external  objects  seemed  to  move,  but  the  direction  of 
their  movements  was  not  observed. 

The  treatment,  which  was  very  effective,  included  dor- 
sal decubitus,  dry  cold  over  the  mastoid  area  of  the  af- 
fected side  and  bromides.  It  should  be  mentioned  that 
the  occasion  on  which  the  car-sickness  manifested  itself 
was  a  hot,  oppressive  day  in  September.  Judging  from 
the  well-known  effect  of  hot  weather  upon  rotation-sick- 
ness and  seasickness,  it  is  highly  probable  that  this  pa- 
tient's  sickness  was   aggravated   by  the   humidity  arid 


SEASICKNESS  489 

closeness  of  the  day.  There  were  no  symptoms  referable 
to  disordered  gastric,  liver,  or  kidney  function;  in  fact, 
the  woman's  physical  condition  was  excellent  both  be- 
fore and  after  the  aural  attack. 

Another  case  worth  recording  is  that  of  Mrs.  S. ,  at 
one  time  a  well-known  professional  dancer.  The  natural 
strength  and  stamina  with  which  nature  had  endowed 
this  lady  was  greatly  enhanced  by  the  daily  training  ne- 
cessitated by  her  profession.  Notwithstanding  all  this, 
however,  and  although  accustomed  from  infancy  to  all 
sorts  of  g}^rations  and  sudden  reversals  of  direction,  this 
individual  was  a  victim  of  seasickness  to  such  an  extent 
that  she  never  fully  recovered  from  her  attacks  until  she 
got  ashore.  At  a  certain  period  of  her  life,  the  exact  age 
could  not  be  ascertained,  her  system  underwent  a  change 
which  rendered  her  immune  to  seasickness.  Thus,  her 
last  attack  of  seasickness  occurred  on  returning  from  Eu- 
rope in  1859.  Between  the  years  1859  and  1869  she  had 
not  been  on  the  water.  In  1869  she  began  to  have  trou- 
ble with  her  ears.  Impairment  of  hearing  followed  im- 
mediately, and  persisted  ever  since.  In  1890  a  relative 
placed  his  yacht  at  her  disposal,  and  it  was  only  after  the 
greatest  amount  of  persuasion  that  she  could  be  induced 
to  venture  aboard  for  a  short  trip.  To  her  great  surprise 
she  found  no  discomfort  in  the  roughest  seas.  Since  that 
time  she  has  travelled  extensively  upon  the  water  under 
extremes  of  weather  conditions,  and  never  experienced 
the  slightest  symptoms  of  seasickness.  Judging  from 
the  experience  gathered  from  nmnerous  cases  in  which 
aural  irrigations  and  other  methods  were  practised,  it 
seems  certain  that  the  vestibular  terminals  undergo  de- 
generation at  an  early  age  in  many  individuals,  although 
Witmaack^s  is  of  the  opinion  that  in  tox&emic  condi- 
tions affecting  the  auditory  nerve,  the  vestibular  branches 
escape.  In  the  individual  under  consideration  the  change 
which  conferred  immunity  from  seasickness  undoubtedly 
was  due  to  degeneration,  whereby  the  receptors  in  the 
ampullae  of  the  semicircular  canals,  and  possibly  also 
those  in  the  maculae  of  the  utricle  and  saccule,  lost  their 
sensibility  so  that  they  no  longer  responded  to  the  stimu- 
lus generated  by  the  movements  of  the  ship. 

These  cases  show  that  even  in  very  neurotic  Individ- 


490  SEASICKNESS 

uals  something  more  than  merely  psychic  factors  is  the 
underlying  cause  of  seasickness.  Admitting  the  impor- 
tant relations  between  the  cerebrum  and  the  cerebellum, 
and  admitting  that  psychic  disturbances  always  accom- 
pany the  severer  forms  of  seasickness,  and  may  even  act 
as  secondary  sources  of  distress  and  discomfort,  often  to 
such  an  extent  as  to  seem  to  be  the  chief  cause  of  the 
malady,  it  must  be  denied  that  such  a  thing  as  seasick- 
ness from  purely  psychic  causes  exists  in  the  sense  that 
psychic  causes  are,  in  the  first  instance,  the  active  factors 
in  the  production  of  the  malady.  Subconscious  or  con- 
scious memories  from  past  experiences  in  seasickness, 
may  so  affect  the  individual  that  very  little  in  the  way  of 
direct  physical  disturbance  suffices  at  times  to  induce 
sickness.  In  such  cases  perhaps  the  sickness  may  be 
considered  as  of  psychic  origin,  whereas  in  reality  the 
cause  in  the  first  instance  was  physical  and  not  psychic. 
Moreover,  in  these  so-called  psychic  cases  there  is  always 
the  necessity  of  some  physical  cause  in  addition  to  the 
psychic  factor;  and  where  the  former  is  wanting,  seasick- 
ness, somatic  or  psychic,  will  not  be  much  in  evidence. 

It  is  well  known  that  disturbances  of  ocular  functions 
can  cause  nausea  and  vertigo  (Stevens  ^so  and  others). 
De  Cyon  ^^  put  prismatic  spectacles  upon  pigeons  and  ob- 
tained disturbances  of  equilibrium  akin  to  those  which 
follow  interference  with  the  semicircular  canals.  In  pig- 
eons which  had  partially  recovered  from  the  effects  of 
operation  upon  the  semicircular  canals,  covering  the  head 
and  eyes  with  a  hood  caused  a  return  of  the  characteristic 
phenomena  (Ewald,^^  De  Cyon^^).  The  most  that  these 
experiments  show  is  that  the  eye  is  a  factor  in  equilibra- 
tion, and  this  is  freely  admitted.  Ocular  defects,  such 
as  errors  of  refraction,  diploplia,  muscular  weakness, 
anything  that  interferes  with  binocular  vision  and  the 
conjugate  action  of  the  eyes  may  cause  disturbances  of 
equilibrium,  nausea,  vertigo,  and  localized  neurasthenia 
of  the  nervous  mechanisms  involved.  The  latter  may  de- 
velop a  generalized  neurasthenia.  But  all  this  does  not 
show  that  ocular  disturbances  are  the  cause  of  seasick- 
ness. Admitting  that  the  eye  is  an  important  source  of 
afferent  impulses  in  the  mechanism  of  equilibration,  and 
admitting  that  in  certain  extreme  cases  of  disturbed  func- 


SEASICKNESS  491 

tion,  the  eye  may  be  the  chief  apparent  factor  in  seasick- 
ness, coupled  perhaps  with  overmastering  psychic  im- 
pressions, as  in  the  case  of  Sumner's  tilted  house,  how 
are  we  to  account  for  the  numerous  cases  of  seasickness 
occurring  in  robust  individuals  with  practically  perfect 
eyes  and  a  normal  condition  of  the  nerv^ous  system  and 
general  musculature  of  the  body?  Merely  because  in  sea- 
sickness the  functions  of  the  eye  and  brain  become  de- 
ranged, and  the  use  of  these  organs  proves  a  source  of 
discomfort  to  the  individual,  are  we  therefore  to  conclude 
that  psychic  or  ocular  disturbances,  or  both  combined, 
are  the  every-day  cause  of  that  seasickness  which  so  few 
escape  when  the  w^eather  conditions  are  sufficiently  severe? 
It  were  as  reasonable  to  say  that,  because  a  hood  placed 
over  the  eyes  of  a  pigeon  recovering  from  the  effects  of 
section  of  the  semicircular  canals,  caused  a  return  of  the 
disturbances  of  equilibrium,  the  phenomena  first  observed 
by  Flourens  are  therefore  due  to  interference  with  vision, 
and  not  to  destruction  of  the  semicircular  canals.  Fi- 
nally, not  eveiy  ocular  defect  causes  vertigo,  nausea,  and 
disturbances  of  equilibrium,  whereas  the  slightest  inter- 
ference with  the  functions  of  the  ampullary  receptors  of 
the  semicircular  canals,  e.g.,  aural  irrigation,  rotation, 
galvanism,  the  application  of  cocain,  touching,  expos- 
ure to  light,  etc.,  have  the  immediate  and  constant  effect 
of  overthrowing  the  equilibrium  and  causing  vertigo, 
nausea,  nystagmus,  increased  salivation,  etc.  On  the 
whole,  even  in  extreme  cases,  the  most  that  can  be  said 
of  the  eyes  as  a  cause  of  seasickness  is  that  they  may  be- 
come secondary  sources  of  disturbance  in  the  malady. 
Whenever  they  seem  to  play  a  leading  role  in  the  causa- 
tion of  seasickness,  it  is  because  of  associated  subcon- 
scious impressions  or  actual  disturbances  of  the  oculo- 
cerebellar  or  vestibulo-cerebellar  mechanisms,  and  even 
then  it  is  not  certain  that  the  prime  cause  at  work  may. 
not  be  the  vestibular  rather  than  the  ocular  mechanisms. 
As  previously  noted,  the  retinal  and  labyrinthine  recep- 
tors and  their  afferent  arcs  make  use  of  the  same  final 
common  paths  in  the  causation  of  nystagmus.  The 
motor  mechanisms  of  the  eyes  are,  therefore,  intimately 
related  to  the  labyrinthine  mechanisms.  Hence,  in  dis- 
turbed conditions  of  the  latter  there  is  also   associated 


492  SEASICKNESS 

disturbance  of  function  in  the  former,  and  looking  at 
moving  objects,  such  as  the  tossing  waves  or  fixing  the 
eyes  as  in  reading,  becomes  very  distressing.  However, 
in  normal  persons,  the  eye  can  stand  prolonged  looking 
at  moving  objects,  without  causing  vertigo  or  sickness, 
provided  the  labyrinthine  mechanisms  are  intact  and  are 
not  interfered  with  in  their  functions.  As  the  primary 
cause  of  seasickness  the  eye,  and  with  it  the  psychic 
factor,  may  therefore  be  excluded. 

Concussion  of  the  organs,  abdominai  or  other,  has 
been  frequently  put  forward  to  explain  the  causation  of 
seasickness.  Undoubtedly,  concussion  and  shaking  about 
can  cause  serious  disturbances  in  certain  individuals. 
The  latter,  however,  will  generally  be  found  to  be  abnor- 
mally constituted  in  some  respect  or  other,  especially  if 
they  react  abnormally  in  this  manner  to  concussions  of 
mild  degree.  Thus  in  many  individuals  who  suffer  from 
carsickness,  recent  uncompensated  labyrinthine  defects 
may  be  found,  or  perhaps  a  localized  or  a  general  neuras- 
thenia. In  grown  people  many  cases  of  carsickness  are 
the  result  mainly  of  fear,  the  cause  being  originally  the 
individual's  experience  at  some  time  in  youth  when,  on 
account  of  acute  ear  disease,  sickness  attended  every  at- 
tempt at  riding  in  cars.  These  experiences  often  leave 
behind  them  impressions  that  subconsciously  dominate 
the  individual  to  such  an  extent  that  in  after  years,  when 
the  labyrinthine  defect  has  been  long  since  recovered  from, 
or  compensated,  the  slightest  excuse  in  the  way  of  a  related 
physical  cause  suffices  to  evoke  the  disagreeable  symp- 
toms. Such  cases  are  frequently  encountered  by  those 
making  special  inquiry  into  the  matter.  The  cases  which 
react  to  mild  concussions,  however  numerous  they  may 
be,  are  few  compared  with  the  number  of  normal  individ- 
uals whom  such  slight  concussions  as  those  experienced 
in  riding  upon  cars  do  not  at  all  affect  disagreeably. 

Severe  blows  upon  the  abdomen  or  severe  injury  to 
any  part  of  the  body  may  cause  disturbances  which  are 
grouped  clinically  under  the  name  of  shock.  The  differ- 
ence between  shock  and  the  condition  presented  by  sea- 
sickness, especially  in  the  earlier  and  milder  stages  of  the 
latter,  is  so  apparent  that  no  conmient  on  this  point  is 
nocessaiy.     Blows  on  the  head,  especially  upon  the  lower 


SEASICKNESS  493 

jaw  as  seen  in  the  prize  ring,  frequently  cause  vertigo, 
vomiting,  muscular  weakness,  etc.  In  these  instances 
the  delicate  mechanisms  of  the  labyrinth  are  the  parts 
chiefly  affected,  and  it  is  to  disturbance  of  the  vestibulo- 
cerebellar mechanisms  that  the  familiar  "grogginess"  is 
mainly  to  be  attributed,  as  well  as  the  muscular  weakness 
that  for  the  time  being  renders  the  contestant  helpless,  a 
ready  victim  for  the  coup-de-grdce.  The  vast  number  of 
those  who  can  withstand  concussion  of  varying  degrees  of 
severity  on  shore,  such  as  that  encountered  in  horseback 
riding,  etc. ,  and  yet  who  are  nevertheless  susceptible  to 
seasickness  from  the  comparatively  mild  degree  of  con- 
cussion from  the  ship's  movements,  points  conclusively 
to  something  other  than  mere  mechanical  concussion  as 
causing  the  phenomena  of  seasickness.  This  was  well 
shown  in  those  auditory  irrigations  in  which  water  of  a 
neutral  temperature,  on  being  allowed  to  flow  into  the 
auditory  canal  from  a  height  in  order  to  determine  the 
effect  of  forcible  impact  of  the  fluid  against  the  drum 
membrane.  The  only  effect  was  a  marked  rise  in  blood- 
pressure  which  any  strong  stimulation  at  the  periphery 
would  have  produced.  No  labyrinthine  phenomena  were 
observed,  although,  when  fluids  of  a  temperature  suffi- 
cient to  evoke  vestibular  phenomena  were  used,  the  effect 
of  the  irrigations  seemed  to  be  enhanced  when  the  fluid 
was  allowed  to  flow  into  the  ear  under  pressure.  Gross 
concussion  of  the  body,  as  a  whole,  plays  a  very  subordi- 
nate part  in  the  etiology  of  seasickness,  though  it  must  be 
admitted  that  in  the  highly  disordered  state  of  the  indi- 
vidual already  suffering  from  seasickness,  concussion 
vibration,  or  any  other  form  of  peripheral  irritation,  may 
be  a  source  of  aggravation  and  distress,  and  may  mate- 
rially retard  recover}^. 

Disturbances  of  the  circulation  have  always  held  a 
prominent  position  in  the  theories  advanced  to  explain 
seasickness.  A  glance  at  the  protocols  will  show  that 
the  subject  was  not  seasick  during  periods  when  the  cir- 
culation was  but  poorly  maintained,  whilst,  when  he  was 
sickest,  e.g.,  on  board  the  Quatre  Freres  and  the  Lady 
Wolseley,  the  blood-pressure  was  well  maintained.  It  is 
admitted  that  in  seasickness  after  a  time  the  circulation 
becomes  demoralized;   but  what   is   sought   now  is   the 


404  SEASICKNESS 

primary  cause  and  not  merely  the  effects  or  associated 
phenomena  of  seasickness.  Moreover,  aural  irrigations 
caused  characteristic  manifestations  of  vestibular  disturb- 
ance even  when  the  action  of  adrenalin  was  at  its  height. 
Rotations  also  produced  the  usual  vertigo,  nausea,  etc., 
when  the  subject  was  under  the  influence  of  nitroglycerin, 
with  its  low  blood-pressure,  and  of  morphin,  with  its 
well-maintained  blood-pressure.  As  before  stated,  circu- 
latory disturbances  are  to  be  considered  as  one  of  the  re- 
sults of  seasickness,  but  they  may  in  turn  assume  impor- 
tance as  secondary  sources  of  exhaustion  and  distress. 

Digestive  disturbances  have  always  been  looked  upon 
by  the  laity  as  the  primary  cause  of  seasickness.  But 
the  fact  that  one  of  the  subjects  "B"  of  the  present  stud- 
ies suffered  at  times  from  indigestion,  and  did  not  at  all 
experience  the  familiar  subjective  phenomena  of  seasick- 
ness, whilst  at  other  times  he  was  dreadfully  seasick 
when  the  stomach,  after  being  irrigated,  was  presumably 
in  a  resting  state,  points  to  deeper  underlying  causes. 
Even  admitting  the  importance  of  digestive  disturbances 
in  seasickness,  the  question  remains  as  to  what  is  the 
cause  and  what  the  mochis  ojyei'andi  of  such  digestive  dis- 
turbances. This,  however,  has  to  be  said  of  digestive 
disturbances  in  seasickness,  and  the  same  holds  true  for 
the  sickness  of  rotations  and  aural  irrigations,  that  when 
once  'the  stomach  function  becomes  disordered  the  pres- 
ence of  stagnant  contents  or  the  ingestion  of  improper 
food  is  a  powerful  and  distressing  factor,  and  remains 
so  until  the  stomach  is  emptied  by  vomiting,  when  the 
sickness  and  distress  seem  to  be  relieved  for  a  time.  The 
symptoms,  however,  especially  those  referable  to  the  head, 
recur  soon  after  in  spite  of  the  empty  condition  of  the 
stomach.  Here,  again,  aural  irrigations  and  galvanism 
by  inducing  all  the  stomach  phenomena  of  seasickness 
with  the  subject  sitting  quietly  or  lying  down,  dispose 
forever  of  those  theories  which  set  up  concussion  of  the  ab- 
dominal organs,  whether  floating  or  otherwise,  as  the  sole 
cause  of  seasickness.  Digestive  disturbances  are,  there- 
fore, to  be  regarded  in  the  first  instance  as  the  effects  of 
seasickness.  When  once  initiated,  however,  they  may 
become  imjjortant  secondary  sources  of  suffering  and 
distress. 


SEASICKNESS  495 

The  theory  of  intra-  and  inter-molecular  disturbances 
of  Rosenbach  may  or  may  not  be  true.  Ultimately  the 
cause  of  seasickness  might  be  stated  in  such  terms,  but 
meanwhile  we  have  a  right  to  know  the  cruder  and  more 
tangible  phenomena  that  intervene.  It  is  a  noteworthy 
fact  that,  as  long  as  the  real  cause  of  an  ailment  remains 
undiscovered,  theorists  deceive  themselves  with  generali- 
zations, which  lay  dovm.  predisposing  and  subsidiary  fac- 
tors and  associated  phenomena  as  the  primary  efficient 
cause.  This  was  what  happened  in  the  case  of  tubercu- 
losis before  the  time  of  Koch's  discovery  of  the  tubercle 
bacillus,  and  this  may  be  expected  to  happen  in  every 
case,  as  long  as  the  real  cause  remains  undetermined. 
The  true  cause  of  such  a  malady  as  seasickness  should 
afford  a  reasonable  explanation  of  the  phenomena  of  most, 
if  not  all,  of  the  cases,  and  of  the  mode  of  their  produc- 
tion. It  should,  moreover,  be  in  accord  with,  and  have 
the  positive  support  of  known  anatomical  and  physiolog- 
ical facts.  Such  a  cause  in  the  case  of  seasickness  is  to 
be  found  in  functional  labyrinthine  disturbances,  due 
directly  to  the  boat's  motions,  and  producing  in  turn 
effects  in  the  manner  which  we  shall  now  endeavor  to 
elucidate. 


CHAPTER    XXXII 

ETIOLOGY   OF  SEASICKNESS    (Continued) 

It  has  been  shown  that  the  phenomena  attending  ro- 
tations, aural  irrigations  and  galvanism  applied  to  the 
mastoid  areas  are  identical  with  the  Flourens  phenomena 
that  follow  section  or  destruction  of  the  semicircular  ca- 
nals in  animals.  Numerous  observations  on  the  circu- 
latory and  gastric  functions,  as  well  as  a  comparison  of 
the  objective  and  subjective  symptoms,  show  an  undeni- 
able similarity  between  the  phenomena  of  seasickness  and 
those  produced  by  rotations,  aural  irrigations,  and  gal- 
vanism. The  only  difference  is  in  the  degree  and  in  the 
mode  of  production.  It  has  been  shown  that  in  aural 
irrigations  and  in  galvanism  the  phenomena  were  caused 
by  a  relative  difference  in  the  degree  of  irritability  of  one 
set  of  ampullary  receptors,  as  compared  with  the  condi- 
tions of  irritability  obtaining  in  the  analogous  opposing 
set  of  ampullary  receptors  in  the  opposite  labyrinth,  and 
that  such  a  difference  in  irritability  upsets  the  balance  of 
the  reflex  vestibulo-cerebellar  mechanisms  by  giving  an 
undue  effect  to  the  normal  impulses  of  equilibration  orig- 
inating in  the  labyrinths,  with  consequent  disturbances  of 
equilibrium,  nystagmus,  muscular  inefiiciency,  alternat- 
ing conditions  of  the  pupil,  varying  conditions  of  the 
vaso-motor  mechanisms,  closure  of  the  pylorus,  nausea, 
vertigo,  increased  salivation,  vomiting,  faintness,  sweat- 
ing, pallor,  paraesthesise,  etc.  In  rotations  identical  re- 
sults were  produced  by  actual  overstimulation  of  the 
terminals  of  one  side,  noted  especially  on  sudden  stop- 
ping and  reversing  of  the  swing.  The  effects  of  rotations 
in  each  of  the  three  cardinal  planes  of  the  body  were 
worked  out  in  detail,  and  constant  relations  were  found 
to  exist  between  certain  sets  of  canals  and  rotations  in  a 
certain  plane.    A  certain  type  of  nystagmus  was  found  to 

496 


SEASICKNESS  497 

correspond  with  rotations  in  a  certain  plane,  as  well  as 
with  certain  kinds  of  aural  irrigations  and  with  certain 
applications  of  the  electrodes  in  galvanism.  Thus  rota- 
tions about  the  long  axis  affect  the  horizontal  canals 
mainly,  and  cause  horizontal  nystagmus.  Hot  and  cold 
aural  irrigations  and  galvanism  similarly  act  mainly 
upon  the  horizontal  canals,  as  owing  to  the  location  of 
the  latter  their  ampullary  receptors  are  more  exposed  to 
the  effects  of  aural  irrigations  and  galvanism  than  the 
receptors  in  the  other  canals.  When  the  irrigations  are 
prolonged,  or  for  some  reason  the  effect  of  the  current  is 
enhanced,  the  ampullary  receptors  of  the  adjacent  supe- 
rior canal  are  affected,  with  the  result  that  a  rotary  ele- 
ment is  added  to  the  horizontal  nystagmus.  A  similar 
rotary  element  is  frequently  met  with  in  the  nystagmus 
of  rotations,  e.g.,  when  the  rotations  about  the  long  axis 
are  not  strictly  confined  to  one  plane. 

In  rotations  it  has  been  shown  that  in  the  case  of  the 
horizontal  canals  the  creation  of  a  tendency  in  the  endo- 
lymph  to  flow  toward  the  ampulla  from  the  canal  was  the 
physiological  stimulus,  whilst  in  the  case  of  the  other 
canals  the  reverse  was  true,  viz.,  the  creation  of  a  ten- 
dency in  the  endolymph  to  flow  from  the  ampullae  toward 
the  canals.  It  was  also  shown  that  each  canal  or  set  of 
canals,  for  in  the  case  of  the  superior  and  posterior  canals 
the  two  superior  canals  are  opposed  to  the  two  posterior, 
was  related  to  certain  sets  of  skeletal  and  ocular  muscles 
through  the  intermedium  of  the  cerebellum,  and  that  any 
stimulation  of  the  ampullary  receptors  in  one  set  more 
than  in  the  other  was  followed  by  reflex  disturbances  of 
equilibrium,  and  when  repeated,  by  nausea,  vomiting, 
increased  salivation,  etc.  These  disturbances  have  been 
shown  to  be  chiefly  due,  not  to  any  simple  reflex  act  in- 
volving Deiters'  or  any  other  single  nucleus,  but  to  re- 
flex acts  taking  place  under  cerebellar  influence,  which 
extends  not  only  to  ocular  and  skeletal  muscles,  but  per- 
haps also  to  visceral,  secretory  and  other  functions  as 
well. 

The  vestibulo-cerebellar  mechanisms  have  been  fully 
discussed  as  well  as  their  relation  to  vertigo.  It  has 
been  shown  that  interference  with  the  afferent  arcs  of  any 
of  the  cerebellar  mechanisms,  whereby  the  balance  be- 


498  SEASICKNESS 

tween  certain  mechanisms  upon  one  side  of  the  body  and 
their  opponents  upon  the  other  side  was  upset,  caused 
vertigo  and  disturbances  of  equilibrium  until  such  inter- 
ference was  overcome  or  compensated.  The  relations  of 
the  vagus  and  glosso-pharyngeal  nerves  to  gastric  move- 
ments were  pointed  out,  irritation  of  the  vagus  causing 
pyloric  closure,  whilst  irritation  of  the  glosso-pharyngeal 
tends  to  cause  relaxation  of  the  cardiac  sphincter.  The 
relation  of  these  two  nerves  to  each  other  and  to  the  sev- 
enth through  their  reception  nuclei  in  the  sensory  portion 
of  the  dorsal  nucleus,  and  the  manifest  association  of  in- 
creased salivation  with  nausea  and  vomiting  point  to  the 
related  motor  nuclei  in  the  nucleus  ambiguus  and  vicin- 
ity, acting  in  conjunction  with  some  higher  centre  (vom- 
iting centre)  as  the  co-ordinating  mechanism  underlying 
this  symptom  complex.  The  relation  of  the  olfactory 
mechanisms  to  nausea  was  pointed  out  and  the  pathways 
indicated  along  which  olfactory  impulses,  which  may  be 
such  important  secondary  features  in  nausea  and  seasick- 
ness, might  travel.  The  widespread  relations  of  the 
peripheral  sensory  nerves  to  the  vaso-motor  and  vomiting 
centres  were  also  discussed. 

A  word  remains  to  be  said  about  vomiting  which,  in 
rotation  sickness  as  well  as  in  seasickness,  is  of  the  cere- 
bellar type.  In  experiments  upon  the  semicircular  canals 
in  sharks  (Sewall^^i)  and  upon  the  cerebellum  in  higher 
animals  (Ferrier^)  no  vomiting  was  witnessed.  In  the 
latter  instance,  however,  as  all  ana3sthetists  know  and  as 
Ferrier  himself  has  frequently  pointed  out,  profound  nar- 
cosis or  shock  tends  to  prevent  vomiting.  Sewall  found 
no  constant  characteristic  disturbances  of  equilibrium 
following  destruction  of  the  semicircular  canals  in  sharks, 
but  found  that  vomiting  frequently  occurred  upon  inter- 
ference with  the  utricle  or  saccule. 

The  experiments  in  which  cold  bilateral  aural  irriga- 
tions were  first  given  to  deaden  the  ampullary  receptors 
of  the  horizontal  canals  and  rotations  then  practised  im- 
mediately, seem  to  indicate  that  labyrinthine  receptors, 
other  than  those  located  in  the  semicircular  canals,  are 
related  to  the  mechanisms  of  vomiting.  Thus,  after  the 
rotations  mentioned  there  was  no  nystagmus  or  vertigo, 
no  deviation  of  the  head,  or  sense  of  dis^ess,  and  yet  the 


"B 


DIAGRAMS  SHOWING  HOW  ROTATION  OR  THE  MOVE- 
MENTS OF  A  SHIP  TEND  TO  CAUSE  REFLEX  DIS- 
PLACEMENT OF  THE  HEAD  AND  EYES  AND  WITH 
THESE  DISTURBANCES  OF  EQUILIBRIUM  VER- 
TIGO,  NAUSEA,    ETC. 

A  and  C  represent  imaginary  transverse  horizontal  sections 
through  the  head  and  the  horizontal  semicircular  canals.  In  A 
the  subject  is  at  rest.  In  C  he  is  just  beginning  to  be  rotated 
from  right  to  left,  as  indicated  by  the  large  arrow.  B  repre- 
sents the  position  of  the  head  and  eyes  with  the  semicircular 
canals  and  their  hair  cells  in  a  state  of  rest,  as  depicted  in  A. 
In  C  the  hair  cells  in  the  left  horizontal  canal  are  slightly  bent 
in  the  direction  from  the  canal  toward  the  ampulla  by  the  ten- 
dency of  the  endolymph  to  flow  in  the  direction  of  the  small  ar- 
row. This  causes  reflex  displacement  of  the  head  and  eyes 
toward  the  right,  as  shown  in  D.  The  dotted  pupils  in  D  indi- 
cate the  short  nystagmic  movements  to  the  left. 


SEASICKNESS  499 

subject  vomited  violently.  As  the  rotations  were  strictly 
about  the  long  axis,  it  is  inferred  that  the  receptors  in 
the  utricle,  and  perhaps  those  in  the  saccule,  were  affected 
and  that  these  were  directly  responsible  for  the  vomiting 
and  alterations  in  the  blood-pressure.  Again  in  rota- 
tions given  with  the  patient  in  recumbency,  vomiting 
was  absent,  but  appeared  at  once  if  the  subject  assumed 
the  erect  posture.  This  seems  also  to  point  toward  the 
conclusion  just  deduced.  It  seems,  therefore,  that  the 
otolithic  apparatus  of  the  vestibule  is  dynamic  as  well  as 
static  in  function,  as  pointed  out  by  Clark,®  and  there 
can  be  little  question  that  these  structures  are  affected  in 
rotations  as  well  as  the  ampullary  receptors  of  the  semi- 
circular canals.  However,  the  hair  cells  in  the  ampullae 
are  much  more  delicate  than  those  in  the  maculae,  and  are 
consequently  more  susceptible  to  mild  grades  of  stimula- 
tion. Hence,  in  the  milder  forms  of  seasickness  it  is 
probable  that  only  the  ampullary  receptors  are  affected, 
whilst  in  rough  weather,  where  the  pitching  and  tossing 
of  the  vessel  are  unusually  severe,  the  receptors  in  the 
utricle  and  saccule  may  also  be  affected. 

Considering  the  chief  motions  of  the  ship  at  sea,  they 
are  found  to  correspond  roughly  with  rotations  about  one 
or  other  of  its  main  axes.  Thus  rolling  may  be  regarded 
as  rotary  movement  about  the  long  axis  and  pitching  as 
rotary  movement  about  the  horizontal  transverse  axis. 
In  the  combination  of  pitching  and  twisting,  known  as 
the  spiral  movement,  an  element  of  rotation  about  the 
vertical  axis  is  added.  Of  the  various  motions  the  most 
effective  for  producing  sickness  is  the  spiral  movement. 
Next  in  order  of  efficiency  comes  pitching.  Rolling  seems 
to  be  the  least  effective  of  all.  The  analogy  of  these 
movements  to  the  movements  of  the  subject's  body  in  the 
rotation  experiments  is  at  once  apparent.  With  the  sub- 
ject lying  on  the  back  and  with  the  long  axis  of  his  body 
parallel  to  the  long  axis  of  the  ship,  the  rolling  move- 
ment gives  a  reproduction  in  miniature  of  rotations  about 
the  long  axis.  The  comparison  may  seem  far-fetched, 
but  it  has  been  sho^Ti  that  in  rotations  little  effect  was 
experienced  when  the  motion  was  equal  and  uniform, 
even  though  rapid,  whilst  great  disturbance  was  produced 
by  the  sudden  stops  and  starts.     In  the  rotating  motions 


500  SEASICKNESS 

of  a  ship,  complete  revolutions  may  not  be  made  as  in 
the  swing,  but  the  stops  and  starts  are  only  too  painfully 
in  evidence,  as  every  victim  of  seasickness  knows.  With 
the  subject  still  on  his  back  and  his  long  axis  parallel  to 
that  of  the  ship,  pitching  gives  a  rotatory  movement,  cor- 
responding to  rotations  in  the  sagittal  plane.  Here, 
again,  the  stops  and  starts  are  what  tend  to  sicken, 
though  in  the  pitching  of  a  ship  the  abruptness  of  these 
depends  much  upon  the  range  of  motion.  When  the 
twist  or  spiral  movement  is  added  to  pitching,  the  new 
element  is  equivalent  to  rotations  in  the  coronal  plane, 
about  a  horizontal  antero-posterior  axis  through  the 
umbilicus. 

With  the  subject  lying  on  the  back,  but  with  his  long 
axis  at  right  angles  to  that  of  the  ship,  the  rolling  mo- 
tion is  equivalent  to  rotation  in  the  sagittal  plane,  pitch- 
ing to  rotation  about  the  long  axis,  and  when  the  spiral 
motion  is  added,  the  new  element  is  equivalent  to  rotation 
in  the  coronal  plane. 

With  the  subject  standing  so  that  the  sagittal  plane  is 
parallel  to  the  long  axis  of  the  ship,  rolling  is  the  equiv- 
alent of  rotations  in  the  coronal  plane,  and  pitching  the 
equivalent  of  rotations  in  the  sagittal  plane,  whilst  an 
added  twist  or  spiral  movement  represents  rotations  about 
the  long  axis.  When  the  subject  stands  with  the  sagittal 
plane  at  right  angles  to  the  ship's  long  axis,  rolling  is 
the  equivalent  of  rotation  in  the  sagittal  plane  and  pitch- 
ing the  equivalent  of  rotation  in  the  coronal  plane,  whilst 
an  added  spiral  movement  represents  rotation  about  the 
long  axis. 

Each  of  these  movements  has  been  shown  to  affect 
definite  portions  of  the  semicircular  canal  apparatus. 
Thus  rotations  about  the  long  axis  affect  the  horizontal 
canal  on  the  side  toward  which  the  rotation  takes  place, 
by  creating  a  tendency  for  a  current  of  endolymph  to  flow 
from  the  canal  toward  the  ampulla,  causing  primarily  a 
displacement  of  the  head  toward  the  shoulder  of  the  op- 
posite side  and  a  primary  nystagmus  in  the  same  direc- 
tion as  that  of  the  rotation.  Sudden  stopping  of  this 
motion  reverses  the  phenomena  with  sickening  effect,  and 
with  a  great  tendency  to  muscular  exhaustion  and  rapid 
alternating  changes  in  the  vaso-motor  tonus.     Rotations 


SEASICKNESS  501 

in  the  sagittal  and  coronal  planes  cause  characteristic 
nystagmus  with  displacements  and  disturbances,  the  ef- 
fect depending  upon  whether  the  superior  or  posterior  set 
of  canals  are  affected  in  the  rotations  in  the  sagittal 
plane,  or  whether  the  right  or  left  superior  canal  is  af- 
fected in  the  rotations  in  the  coronal  plane.  It  was  found 
that  rotations  about  the  long  axis,  with  the  subject  sit- 
ting upright,  were  the  most  efficient  in  causing  sickness, 
and  this  corresponds  with  what  is  known  of  the  effects  of 
the  spiral  movements  of  a  ship  upon  an  individual  sitting 
upright  or  standing.  In  rotations  and  irrigations  prac- 
tised with  the  subject  in  recumbency  the  effect  was  al- 
ways less  than  when  rotations  and  irrigations  were  prac- 
tised with  the  subject  sitting  upright,  whilst  irrigations 
or  galvanism  over  the  mastoid  areas,  practised  with  the 
subject  standing,  gave  the  quickest  and  sharpest  reac- 
tions. Here,  again,  the  results  of  experiment  are  corrob- 
orated by  common  experience.  With  the  subject  in  re- 
cumbency, rotations  when  brisk  and  frequently  repeated, 
and  irrigations  with  very  hot  or  very  cold  water  and 
frequently  repeated,  registered  their  effects  upon  the  cen- 
tral nervous  system;  and,  although  the  subject  was  fre- 
quently not  sufficiently  affected  as  to  make  him  very  sick, 
yet  on  assuming  the  erect  position,  he  almost  invariably 
vomited.  Once  more  common  experience  corroborates 
experimental  findings.  Many  passengers  on  the  first 
night  at  sea  go  to  bed  feeling  comfortable,  and  awake  in 
the  morning  to  find,  on  attempting  to  stand  up,  that  dur- 
ing the  night  something  had  taken  place  which  had  paved 
the  way  for  the  extreme  distress  that  culminates  in 
vomiting. 

In  the  upward  and  downward  motions  of  a  ship,  rec- 
tilinear movement  must  also  be  taken  into  consideration, 
as  such  movements,  when  violent,  undoubtedly  affect  the 
otolithic  apparatus  in  the  utricle  and  saccule,  and  en- 
hance the  efficiency  of  the  spiral  and  pitching  movements 
in  causing  seasickness.  In  marked  downward  and  up- 
ward movements  the  normal  reflexes  (other  than  those 
mediated  through  the  labyrinth),  controlling  equilibrium, 
are  also  markedly  disturbed.  The  result  is  a  twofold 
disturbance  of  equilibrium  by  (1)  distortion  of  the  nor- 
mal afferent  impulses  to  the  cerebellum,  and  by  (2)  dis- 


502  SEASICKNESS 

tort  ion  cf  the  normal  impulses  to  the  other  centres,  con- 
trolling gross  movements  of  station  and  equilibrium,  e.g., 
the  optic  thalamus,  etc.  Thus,  when  a  part  of  the  ship, 
having  attained  its  maximum  height  in  pitching,  com- 
mences its  rapid  descent,  the  afferent  kinaesthetic  impulses 
from  the  proprioceptors  in  the  lower  limbs  misrepresent 
the  true  condition  of  affairs  and  the  corresponding  effer- 
ent motor  impulses  sent  out  in  response,  are  out  of  all 
proportion  to  the  actual  needs.  The  result  is  a  tempo- 
rary loss  of  the  sense  of  position  of  those  parts  which 
form  the  essential  basis  for  cerebellar  action  in  the  main- 
tenance of  equilibrium.  Disturbance  of  the  afferent  im- 
pulses from  the  cord  to  the  cerebellar  and  other  centres 
might,  perhaps,  be  compensated  by  the  semicircular  ca- 
nals, as  Bickel  ^82  has  shown  by  division  of  the  posterior 
spinal  nerve  roots  in  the  dog.  In  seasickness,  however, 
the  semicircular  canals  themselves  are  so  affected  that 
they  could  scarcely  be  expected  to  compensate  defects  in 
other  mechanisms. 

The  relations  of  each  semicircular  canal  or  set  of  ca- 
nals to  definite  groups  of  skeletal  and  ocular  muscles,  as 
well  as  the  relations  of  the  vestibulo-cerebellar  mechan- 
isms to  other  important  functions  have  been  fully  dis- 
cussed in  previous  ^chapters.  The  frequent  absence  of 
well-marked  nystagmus  in  seasickness  is  no  reason  for 
making  a  fundamental  distinction  between  seasickness 
and  rotation-sickness.  In  some  persons  the  nystagmus 
in  rotations  is  slight  and  transitory.  Similarly  in  many 
persons  a  mild  galvanic  current  will  effectually  sicken  the 
individual  without  causing  much  apparent  nystagmus. 
This  is  especially  true  if  the  current  be  opened  and  closed 
frequently  for  a  long  time  without  rest  or  intermission. 
Moreover,  even  in  the  milder  grades  of  dizziness  or  ver- 
tigo nystagmus  will  always  be  found  if  searched  for  with 
the  ophthalmoscope. 

The  views  herein  set  forth  as  to  the  etiology  of  sea- 
sickness receive  corroboration  from  various  sources. 
Thus  in  elderly  persons  whose  auditory  nerves  are  well 
known  to  undergo  atrophy  and  degeneration,  there  is  a 
comparative  immunity  from  seasickness  as  well  as  from 
the  sickness  that  comes  from  aural  irrigations,  etc.  Tests 
have  been  frequently  made  upon  such  individuals  with 


SEASICKNESS  503 

aural  irrigations  and  with  galvanism,  and  it  was  gener- 
ally found  that  they  had  diminished  susceptibility.  The 
immunity  of  deaf-mutes  to  rotation  sickness,  as  well  as 
the  acquired  immunity  and  susceptibility  in  the  four 
cases  already  alluded  to,  afford  direct  evidence  of  the  role 
of  the  vestibular  nerve  elements  in  the  causation  of  sea- 
sickness. 

It  should  always  be  remembered  that  where  the  laby- 
rinthine receptors  are  equally  affected  on  both  sides 
simultaneously,  there  is  no  apparent  disturbance  of  equil- 
ibrium. Thus,  in  persons  who  rapidly  become  almost 
completely  deaf,  there  may  be  no  vertiginous  s}Txiptoms. 
This  happened  in  \yitmaack's  ^^  case,  where  sudden  bi- 
lateral deafness,  occurring  in  a  young  phthisical  subject, 
was  caused  by  toxic  acoustic  neuritis.  It  was  this  case 
chiefly  that  enabled  Witmaack  to  deduce  the  important 
conclusion  that  deafness  and  disturbances  in  the  laby- 
rinth, occurring  in  certain  diseased  conditions  and  in 
poisoning  by  certain  drugs,  were  due,  not  to  circulatory 
changes  (anemia  and  hypersemia)  of  the  labyrinth,  but 
to  degeneration  of  the  acoustic  nerve  fibres  "up  to  the 
lamina  spiralis  and  the  spiral  ganglion. "  It  is  safe  to 
say  that  in  Witmaack 's  case  the  equal  and  uniform  affec- 
tion of  the  labyrinth  on  either  side  was  responsible  for 
the  absence  of  vertigo,  although  Witmaack  found  but  lit- 
tle involvement  of  the  vestibular  trunks.  Clinical  obser- 
vations, especially  those  made  with  aural  irrigation  tests, 
show  conclusively  that  in  degenerations  of  the  cochlear 
nerve  the  vestibiilar  is  also  affected,  though  perhaps  to  a 
less  extent. 

The  anatomical  and  physiological  relations  of  the  ves- 
tibular nerve  to  the  medullary  nuclei  and  the  cerebellum, 
as  well  as  to  the  higher  centres,  have  been  fully  discussed 
in  previous  chapters.  In  seasickness  the  paths  along 
which  impulses  originating  in  the  ampullary  receptors  of 
the  canals,  and  in  the  receptors  of  the  otolithic  apparatus  of 
the  vestibule,  are  precisely  the  same  as  those  along  which 
similar  impulses  travel  in  rotation-  and  aural  irrigation- 
sickness,  the  modus  operaiidi  being  the  same  in  each  in- 
stance. Enhanced  irritability  (lowered  threshold  value) 
of  one  set  of  ampullary  or  macular  receptors,  as  compared 
with  the  condition  of  the  analogous  opposing  set  of  recep- 


504  SEASICKNESS 

tors  in  the  labyrinth  of  the  opposite  side,  disturbs  the 
balance  of  the  vestibiilo-cerebellar  reflex  mechanisms, 
which  are  constantly  in  operation,  serving  to  maintain 
automatically  the  upright  position  of  the  body  and  to 
steady  the  trunk  and  head  upon  the  fixed  lower  supports. 
The  result  is  vertigo,  nystagmus,  etc. ,  and  a  disturbance 
of  the  normal  mechanisms  of  equilibrium  whereby  the  lat- 
ter are,  to  a  certain  extent,  overthrown,  necessitating  the 
constant  employment  of  voluntary  effort  to  counteract  dis- 
placements. In  this  manner  an  undue  amount  of  tension 
is  put  upon  the  whole  nervous  and  muscular  systems. 
But  besides  controlling  the  skeletal  muscles  in  acts  of 
balancing,  the  labyrinthine  mechanisms  stand  in  close 
relation  to  gastric  and  intestinal  movements.  Labyrin- 
thine impulses  reach  the  cerebral  and  medullary  centres 
through  the  cerebellum,  or  perhaps  in  the  case  of  im- 
pulses originating  in  the  macular  receptors  by  more  direct 
pathways.  In  this  way  labyrinthine  impulses  affect  the 
vagus,  glosso-pharyngeal,  and  facial  motor  neurones 
through  the  vomiting  centre,  as  well  as  the  vaso-constric- 
tor  and  other  centres  of  higher  and  lower  levels.  In  or- 
dinary mild  cases  of  seasickness  the  primary  effect  is  one 
of  stimulation.  Repetition  or  increased  intensity  of  the 
stimulus  sooner  or  later  causes  the  well-known  functional 
disturbances  in  the  related  organs  and  mechanisms.  The 
nature  and  mode  of  production  of  these  disturbances  have 
been  fully  discussed  in  the  chapters  devoted  to  rotation- 
sickness.  The  inevitable  result  is  a  general  state  of  ex- 
haustion, with  demoralized  circulatory  and  gastric  func- 
tion and  a  general  weakness  and  irritability  whereby  the 
slightest  mental  or  physical  effort  causes  discomfort  and 
ordinary  sights,  sounds,  odours,  etc.,  become  distressing 
and  intolerable. 

The  exhausting  effect  of  interference  with  the  cerebel- 
lum has  long  ago  been  demonstrated  by  Weir-Mitchell,  ^2 
Luciani,®^  and  others.  Failure  and  perversion  of  gastric 
function  become  in  seasickness  a  secondary  source  of 
distress  by  causing  a  deficient  supply  of  nourishment  to 
the  body  as  a  whole,  and  by  a  constant  flow  of  afferent 
impulses  from  the  interior  of  the]organ  through  the  vagus 
to  the  sensory  portion  of  the  dorsal  nucleus,  where  the 
sensory  vagus  centre  is  in  close  relation  with  the  sensory 


SEASICKNESS  505 

centres  of  the  facial  and  glosso-pharyngeal  nerves,  and 
with  the  cerebelhim  and  higher  centres.  Such  afferent 
impulses  originating  in  the  gastric  receptors  tend  to 
maintain  a  constant  state  of  nausea  and  increased  saliva- 
tion, and  keep  the  victim  in  a  condition  of  extreme 
wretchedness  on  the  verge  of  vomiting.  Disturbed  circula- 
tory function  also  becomes  an  important  factor,  causing 
in  the  medullary  and  cerebral  centres  a  blood-supply  that 
is  irregular  or  insufficient  to  meet  the  needs  of  normal 
metabolism  and  the  removal  of  waste  products.  The  use 
of  the  eyes,  especially  in  looking  at  moving  objects,  is 
another  source  of  distress;  as,  under  ordinary  circum- 
stances, in  looking  at  moving  objects,  the  ocular  movements 
are  mainly  executed  by  the  oculo-cerebellar  mechanisms, 
aided  by  the  vestibulo-cerebellar  mechanisms,  both  sets 
of  mechanisms  using  the  same  final  common  paths.  In 
seasickness  the  cerebellar  centres,  and  indeed  the  whole 
individual,  are  in  a  state  of  disorganization,  with  marked 
inability  and  disinclination  for  work  of  any  kind.  The 
well-known  influence  of  odours  upon  those  suffering  from 
seasickness,  as  well  as  the  perversion  of  the  sense  of  smell, 
are  to  be  accounted  for  by  the  instability  and  abnormal 
irritability  of  the  cerebral,  cerebellar,  and  medullary 
centres,  and  chiefly,  perhaps,  of  the  vomiting  centre  and 
those  centres  located  in  the  dorsal  nucleus.  The  fibre 
paths,  along  which  such  olfactory  impulses  may  travel, 
have  been  already  discussed. 

Many  authors  of  the  present  day  attribute  seasickness 
in  a  vague  and  general  way  to  unaccustomed  irritations 
of  the  optic,  labyrinthine,  and  kinsesthetic  mechanisms. 
As  previously  pointed  out,  under  certain  conditions,  the 
eyes  might  possibly  be  the  prime  cause  of  seasickness; 
but,  in  the  light  of  our  present  knowledge,  the  average 
eye  is  not  nearly  so  susceptible  to  the  effects  of  irregular 
motions,  with  sudden  stops  and  starts  as  the  labyrinthine 
apparatus.  In  rotations,  aural  irrigations,  and  in  gal- 
vanism applied  to  the  mastoid  areas,  the  individual  may 
be  sickened  when  the  eyes  are  excluded  by  closing  or  cov- 
ering them;  whilst  if  the  labyrinth  be  absent  on  both 
sides,  or  incapable  of  functioning,  neither  animals  nor 
men  are  susceptible.  In  order  to  prove  that  the  eyes  or 
any  other  organ  may  be  the  prime  cause  of  seasickness, 


fi06  SEASICKNESS 

it  would  be  necessary  to  exclude  first  the  effects  that  are 
constantly  present  in  every  case  in  which  there  exists 
even  jDait  of  a  functionating  labyrinth.  It  has  been 
demonstrated  in  rotations  and  aural  irrigations  that  dis- 
turbance of  the  vestibulo-cerebellar  balanced  mechanisms 
is  always  associated  with  nystagmus.  The  ocular  appar- 
atus is,  therefore,  to  a  greater  or  less  extent  involved  sec- 
ondarily in  the  labyrinthine  irritations  which  cause  sea- 
sickness, and  is  frequently,  if  not  always,  involved  to 
some  extent  in  the  causation  of  the  distressing  symptom, 
vertigo.  All  this,  however,  merely  shows  that  the  eye 
may  be,  and  often  is,  an  important  secondary  factor  in 
the  etiology  of  seasickness. 

The  "  kina3sthetic  sense"  is  a  term  designed  to  cover 
afferent  impulses  from  muscles,  joints,  tendons,  etc. 
These  impulses  originate  in  the  proprioceptors  of  the 
various  organs.  We  have  seen  that  the  cerebellum  by 
means  of  its  reflex  mechanisms  adjusts  and  controls  the 
muscles  involved  in  acts  of  equilibration,  and  that  it 
does  so  by  means  of  its  afferent  and  efferent  paths.  The 
chief  afferent  cerebellar  paths  are  (1)  the  vestibular,  (2) 
the  ocular  (including  optic),  (3)  the  kina3sthetic,  and 
(4)  the  cerebral.  The  cerebellar  mechanisms  are  daily 
subjected  to  all  sorts  of  jars  and  motions  by  people  on 
shore,  and  seldom  produce  phenomena  in  any  way  resem- 
bling those  of  seasickness.  As  before  stated,  it  has  been 
shown  by  Bickel  that,  in  the  dog  after  section  of  the  pos- 
terior nerve  roots,  the  semicircular  canals  can  compensate 
the  loss  of  spinal  afferent  cerebellar  impulses.  As  the 
cerebelhim  ordinarily  controls  in  a  reflex  manner  many 
of  the  acts  involved  in  equilibration,  impairment  of  cere- 
bellar function  throws  an  unusual  and  exhausting  strain 
on  the  centres  in  the  Rolandic  regions.  In  seasickness 
when  cerebellar  exhaustion  has  set  in,  the  kinsesthetic 
mechanisms  may  be  a  secondary  source  of  irritation  on 
account  of  functional  disturbance,  and  may  thereby  aid 
in  maintaining  or  aggravating  the  disorder.  In  certain 
movements  of  the  boat,  e.g.,  sudden  prolonged  upward 
or  downward  motions  the  function  of  the  kinsesthetico- 
thalamic  paths  may  be  involved  leading  to  a  temporary 
loss  of  coordination  in  the  under  supports  of  the  body 
with  the  result  that  the  cerebellum  has  no  secure  base 


SEASICKNESS  507 

toward  which  to  make  its  equilibratory  adjustments.  It 
is  possible  that  this  may  be  occasionally  a  primaiy^  factor 
in  the  causation  of  seasickness,  but  if  it  ever  is  it  never 
attains  to  more  than  subsidiaiy  importance.  In  loco- 
motor ataxia,  patients  standing  erect  with  the  feet  close 
together,  do  not  become  dizzy  or  nauseated  when  the  eyes 
are  closed,  but  simply  sway  or  perhaps  fall.  This  shows 
the  relation  the  eyes,  under  certain  circumstances,  may 
bear  to  the  optic  thalamus  and  to  the  coordination  of  the 
feet  and  other  members.  Here  again  is  another  way  in 
which  the  eyes  in  seasickness  may  be  unusually  strained, 
and  ultimately  become  a  secondaiy  source  of  irritation 
and  exhaustion.  Helmholtz  ^ss  gays :  ' '  One  feels  the  trac- 
tion of  gravity  (on  board  ship)  now  apj)arently  to  the 
right,  now  apparently  to  the  left,  now  forwards  and  now 
backwards,  because  one  is  no  longer  able  to  find  with  his 
eyes  the  direction  of  the  vertical.  Only  after  long  prac- 
tice, as  I  myself  can  testify,  does  one  come  to  use  gravity 
as  an  exclusive  means  of  orientation,  and  only  then  does 
the  vertigo  cease."  Regarded  from  any  standpoint 
neither  the  eyes  nor  the  kinsesthetic  sense  can  be  seriously 
considered  as  more  than  secondary,  or  at  most  subsidiary 
primary  factors  in  the  causation  of  seasickness.  Almost 
any  organ  or  function  may  be  so  affected  as  to  become 
prominent  as  a  symptomatic  feature  and  source  of  dis- 
tress. It  is  to  misinterpretation  of  such  occurrences  we 
are  indebted  for  the  many  theories  that  attribute  seasick- 
ness to  any  one  of  the  numerous  secondary  factors  in- 
volved. Throughout  the  ages,  seasickness  has  been  much 
of  a  puzzle  to  mankind.  The  first  step  toward  the  actual 
solution  of  the  problem  was  made  by  Flourens  in  1824, 
when  he  divided  the  semicircular  canals  in  pigeons  and 
rabbits. 


CHAPTER  XXXIII 

ON   THE   OCCURRENCE  OF   SEASICKNESS 

The  literature  of  seasickness  teems  with  conflicting 
reports,  as  to  the  immunity  or  susceptibility  of  certain 
groups  of  individuals,  the  cause  being  failure  to  recognize 
the  various  shades  and  degrees  of  severity  of  the  condi- 
tion. It  is  commonly  agreed  that  those  of  the  nervous  or 
neurasthenic  type  are  more  susceptible  than  those  of 
coarser  fibre  (Beard  ^^2)  but  little  reliance  is  to  be  placed 
on  such  distinctions  since,  as  we  have  seen,  very  neurotic 
individuals  with  degenerated  labyrinthine  nerves  may 
show  absolute  immunity.  Children,  most  authors  agree, 
are  comparatively  immune.  Here  again  is  room  for 
doubt.  Children  old  enough  to  run  about,  are  frequently 
affected,  but  as  a  rule  recover  rather  quickly  owing  per- 
haps to  the  mental  and  physical  conditions  peculiar  to 
childhood.  Very  young  children,  such  as  infants  in 
arms,  are  seldom  sick,  either  because  they  are  not  called 
upon  to  perform  much  in  the  way  of  acts  of  equilibration, 
or  because  of  the  undeveloped  condition  of  the  mechan- 
isms of  equilibration.  It  must  be  remembered,  however, 
that  children  cutting  teeth  suffer  occasionally  from  ver- 
tigo and  nystagmus  and  that  infants  have  been  actually 
seen  to  suffer  from  what  was  undoubtedly  seasickness. 
In  children  it  frequently  happens  that  an  extreme  condi- 
tion of  nervousness  develops  at  sea.  Thus  a  girl  of  eight 
suffered  greatly  from  inability  to  rest  or  relax  her  feet 
properly  in  bed  at  night,  and  constantly  cried  out  to  her 
mother  that  she  did  "not  know  what  to  do  with  her  feet 
for  they  wouldn't  keep  still  in  any  position."  This 
symptfjm  will  be  readily  appreciated  by  those  in  whom 
overtense  conditions  of  the  nervous  system  do  not,  at 
times,  permit  proper  relaxation  of  the  muscles. 

Old  age  is  frequently  immune  for  numerous  reasons, 

508 


SEASICKNESS  509 

but  more  particularly  because  of  the  rule  that  in  advan- 
cing years  there  is  a  tendency  to  arteriosclerosis  and  to 
bilateral  atrophy  and  degeneration  of  the  auditory  nerve. 
Those  suffering  from  chronic  wasting  diseases  and  from 
continued  excesses  in  alcohol  also  seem  to  have  a  relative 
immunity.  Here  the  cause  is  deterioration  of  the  ves- 
tibulo-cerebellar  mechanisms  whereby  they  do  not  so 
readily  respond  to  labyrinthine  stimulation  and  depres- 
sion, or  deterioration  of  the  cerebral  and  medullary  centres 
whereby  the  labyrinthine  irritation  is  less  effective  in 
evoking  the  phenomena  of  the  malady  in  their  full  sever- 
ity. And  here  it  is  significant  that  in  any  one  of  these 
conditions  degeneration  of  the  auditory  nerves  may  occur 
as  Witmaack  ^^  has  shown. 

Some  apparently  normal  individuals  appear  to  enjoy 
immunity,  the  cause  being  peculiarities  of  structure  or 
function  of  the  vestibulo-cerebellar  mechanisms  or  of  the 
related  cerebral  and  medullary  centres.  Similar  immu- 
nity to  a  certain  degree  has  been  observed  in  some  individ- 
uals in  experiments  wdth  rotations,  aural  irrigations  and 
galvanism.  Such  individuals  have  a  natural  or  acquired 
power  of  resisting,  to  a  certain  degree,  the  effects  of  cer- 
tain forms  of  stimulation  peculiar  to  seasickness  just  as 
ordinary  individuals  offer  differing  degrees  of  resistance 
to  various  other  forms  of  stimulation  by  alcohol,  tobacco, 
pain,  etc.  Probably  no  one  with  functioning  labyrinths 
is  totally  immune  to  seasickness  under  all  conditions  of 
circumstance  and  weather.  It  is  certain  that  no  one  is 
immune  to  rotations  of  all  grades  of  severity  unless  both 
auditory  nerves  have  degenerated,  or  both  labyrinths  have 
been  excised  as  in  many  of  the  experiments  which  have 
been  performed  upon  animals.  It  is  a  common  popular 
error  to  suppose,  that  because  an  individual  is  robust 
and  healthy  he  will  not  therefore  fall  a  victim.  Seasick- 
ness in  ordinary  conditions  of  health  is  primarily  the  re- 
sponse of  the  organism  to  repeated  and  irregular  forms  of 
labyrinthine  stimulation.  Predisposition  to  seasickness, 
therefore,  merely  implies  ready,  alert  reflex  mechanisms, 
and  is  in  no  way  directly  related  to  the  health  or  strength 
of  the  individual  in  so  far  as  its  primary  causation  is 
concerned.  In  fact  so  common  is  seasickness  amongst 
normal  individuals  that  the  burden  of  proof  rests  with 


610  SEASICKNESS 

those  who  are  immune  to  prove  that  they  are  free  from 
abnormality. 

Trainers  of  athletes  of  extensive  experience  and  of 
world-wide  reputation  have  given  the  information  that 
seasickness  occurs  amongst  sprinters,  distance  runners, 
weight  throwers,  jumpers  and  football  players  alike  indis- 
criminately. Several  athletes  professional  and  amateur 
were  consulted,  and  the  information  obtained  corroborated 
that  of  the  trainers.  The  sea  has  frequently  taken  the 
"edge"  off  athletes  in  condition,  so  that  after  the  voyage 
it  took  some  time,  in  some  instances  a  long  time,  before 
the  individuals  came  up  to  their  usual  performances. 
One  individual,  a  professional  pugilist  whose  chief  merit 
consisted  in  his  extraordinary  ability  to  "withstand  pun- 
ishment" without  being  "knocked  out"  sent  in  a  face- 
tious reply  in  which  he  expressed  the  opinion  that  "wet 
goods"  (alcohol)  had  more  to  do  with  the  causation  of 
seasickness  than  any  other  factor.  This  individual  was 
very  probably  immune  to  seasickness  and  his  statement 
regarding  the  relation  of  alcohol  to  the  causation  of  sea- 
sickness, though  flippant  in  form,  in  all  probability  rep- 
resents conclusions  drawn  from  personal  experience.  An- 
other pugilist  noted  also  for  his  ability  to  resist  "the 
knock-out"  blow  reported  that  he  had  never  been  affected 
by  seasickness.  This  individual,  however,  has  descended 
from  a  long  line  of  ancestors  famed  for  their  exploits  on 
sea. 

Several  professional  equilibrists,  acrobats  and  tumblers 
were  interrogated  by  mail.  Not  one  reply  was  received. 
This  fact  inclines  one  to  the  belief  that  men  of  these  call- 
ings are  prone  to  seasickness  and  consider,  perhaps,  that  it 
might  be  a  reflection  upon  their  professional  ability  to 
own  up  to  the  fact.  A  famous  distance  runner  who  holds 
many  records  also  failed  to  send  in  a  reply.  The  author 
saw  this  man  in  the  throes  on  a  transatlantic  trip.  It  is 
well  known,  however,  that  famous  athletes  of  every  de- 
scription are  subject  to  seasickness. 

The  question  as  to  the  immunity  of  animals  has  been 
dealt  with  extensively  in  the  literature  to  which  it  lends 
an  amusing  and,  at  all  times,  interesting  feature.  Here, 
as  elsewhere,  a  great  difference  of  opinion  prevails.  The 
general  consensus  is  that  most,  if  not  all,  animals  suffer 


SEASICKNESS  511 

from  the  malady.  The  opportunity  of  studying  the  ques- 
tion directly,  not  having  presented  itself,  inquiry  was 
made  from  those  who  not  only  had  the  opportunity,  but 
were  otherwise  qualified  to  form  an  opinion.  Dr.  G.  G. 
Flemjmg  of  the  White  Star  Liner  Teutonic  was  sur- 
geon in  charge  of  the  vessel  which  brought  over  to  the 
London  Zoological  Gardens  the  Australian  collection  of 
animals  amounting  to  about  5,000  specimens.  The  doc- 
tor stated  that  most  of  the  animals  came  down  with  com- 
mon ordinary  seasickness  just  like  human  beings  and 
many  died  from  the  malady. 

A  fellow  traveller  whose  business  was  concerned  in 
taking  horses  from  America  to  Europe  and  selling  them 
there,  was  next  interrogated.  This  individual  stated  off- 
hand that  animals  do  not  get  seasick.  Upon  closer  ques- 
tioning he  stated  that  his  experience  was  confined  to 
horses  of  the  draft  variety  and  he  qualified  his  former 
statement  by  saying  that  animals  do  not  get  seasick — if 
you  know  how  to  feed  them  properly.  It  was  later  dis- 
covered that  this  man's  conception  of  seasickness  was  a 
disturbance  of  function  of  such  intensity  as  to  threaten 
the  life  of  his  animals. 


CHAPTER  XXXIV 

THE   EFFECTS   OF   SEASICKNESS  AND   THEIR   RELA- 
TION  TO   DISEASED   CONDITIONS 

The  effects  of  seasickness  upon  the  nervous  system 
and  upon  the  circulatory  and  digestive  functions  have 
been  fully  set  forth  and  commented  upon  in  those  chap- 
ters dealing  with  observations  on  seasickness. 

A  glance  at  the  protocols  will  convince  the  most  skep- 
tical that  seasickness  occurring  in  normal  individuals 
throws  an  enormous  strain  ujDon  the  circulatory  mechan- 
isms and  especially  upon  the  heart  which  more  and  more 
has  to  assume  the  burden  of  maintaining  the  blood-pres- 
sure as  the  vaso-motor  system  becomes  exhausted.  And 
not  only  is  the  heart  overworked  but  on  account  of  failure 
of  the  digestive  functions  it  is  usually  under-nourished 
and  frequently  even  starved.  Look  at  the  question  as  we 
may,  whether  we  attribute  the  condition  of  the  circula- 
tion to  stuffy  cabins,  warm  weather,  the  motions  of  the 
boat  or  to  whatever  cause,  the  effects  upon  the  heart  are 
always  a  matter  of  grave  concern.  And  here  the  question 
arises:  If  these  things  occur  in  healthy  adults,  how  are 
the  effects  of  seasickness  upon  the  degenerated  heart  mus- 
cle or  upon  a  generally  enfeebled  organism  to  be  esti- 
mated? No  one  would  think  of  allowing  an  individual 
of  middle  age  and  with  a  diseased  or  enfeebled  heart 
muscle  to  engage  in  a  physical  contest  where  the  strain 
might  be  severe  and  prolonged.  And  yet  it  is  a  common 
thing  for  those  recovering  from  protracted  or  severe  illness 
to  be  sent  to  sea  to  complete  the  restoration  to  health, 
without  the  practitioner  giving  serious  thought  to  the 
special  strain  that  a  voyage  might  entail  upon  the  organ- 
ism and  especially  upon  the  heart.  Many  individuals 
past  the  meridian  of  life,  have  been  seriously  injured  by 
injudicious  travelling  on  sea.     It  is  scarcely  an  exaggera- 

512 


SEASICKNESS  513 

tion  to  say  that  a  large  percentage  of  the  deaths  that  occur 
at  sea  are  attributable  directly  or  indirectly  to  the  effects 
of  seasickness.  Sometimes  it  is  said  that  seasickness  is 
not  an  unmitigated  evil  and  that  in  certain  cases  it  may 
do  an  individual  good.  Such  a  statement  may  perhaps 
be  occasionally  permissible  for  its  psycho-therapeutic 
effect,  but  it  would  be  a  difficult  task  to  convince  any 
unbiassed  mind  that  the  conditions  revealed  by  the  proto- 
cols representing  actual  observations  taken  at  sea,  could, 
in  any  way  whatever,  be  a  benefit  to  the  individual.  On 
the  contrary,  it  is  manifestly  apparent  that  they  might 
permanently  injure  him  and  in  presence  of  actual  disease, 
whether  acute  or  chronic,  so  handicap  the  patient  as  to 
seriously  mar  the  prospects  of  ultimate  complete  recovery. 

The  effects  of  seasickness  upon  pregnant  women  are 
frequently  alluded  to  in  the  literature,  many  cases  of 
abortion,  miscarriage,  and  premature  labour  being  cited. 
There  is  a  group  of  cases  of  amenorrhoea  which  gynecolo- 
gists attribute  to  change  of  climate.  The  condition  de- 
velops usually  in  domestics  of  foreign  birth  and  makes 
its  first  appearance  when  the  individual  leaves  her  home 
to  earn  her  living  in  distant  lands.  Judging  from  the 
frequency  of  amenorrhoea  after  sea  voyages  and  remem- 
bering the  exposure  to  which  steerage  passengers  when 
seasick  are  submitted  as  well  as  the  profound  impression 
which  seasickness  makes  upon  the  nervous  system  and 
indeed  upon  the  whole  organism,  it  is  perhaps  more 
reasonable  to  attribute  this  form  of  amenorrhoea  to  the 
effects  of  seasickness  and  exposure  rather  than  to  mere 
change  of  climate. 

The  effects  of  seasickness  on  the  nervous  system  have 
been  frequently  alluded  to  in  previous  chapters.  The 
psychic  depression  is  frequently  so  extreme,  and  cerebral 
function  so  completely  perverted,  that  self-control  becomes 
an  impossibility.  Many  of  the  numerous  cases  of  suicide 
that  occur  at  sea,  have  for  their  immediate  cause  this 
psychic  depression.  Suicide  on  land,  like  other  grave 
errors  in  conduct,  is  seldom  the  result  of  sudden  inspira- 
tion. The  thought  of  it  has  previously  been  entertained 
and  examined.  Comparisons  have  been  instituted  and 
some  sort  of  hypothetical  conclusion  reached  as  to  its 
feasibility  under  certain  circumstances.     Every  individual 


514  SEASICKNESS 

at  some  time  or  other,  turns  over  in  his  mind  the  thought 
of  suicide  and  the  mental  attitude  he  assumes  toward  it, 
though  it  appears  trivial  perhaps  at  the  time,  may,  later 
on,  become  a  matter  of  the  gravest  import  in  conditions 
of  psychic  derangement.  Many  go  to  sea,  with  no 
thought  of  suicide  beyond  these  hypothetical  conclusions, 
retained  as  subconscious  memories,  and  in  the  psychic 
depression  induced  by  a  mild  grade  of  seasickness,  the 
incapacitated  mind  erroneously  concludes  that  the  requi- 
site conditions  have  arisen  which,  according  to  previous 
reasonings,  render  suicide  feasible  and  proper.  Thus  it 
happens  that  individuals  pay  with  their  lives  the  penalty 
of  poorly  regulated  unsystematic  habits  of  thought. 
Thoughts  in  a  great  measure  make  us  what  we  are  and 
it  is  the  individual's  business  in  every  instance  to  see 
that  his  thoughts  do  not  tend  to  unmake  himself  or 
others. 

From  these  considerations  it  is  manifest  that  a  serious 
responsibility  rests  with  the  physician  who  recommends 
sea  voyages  in  conditions  in  which  the  "reserve  margin' ' 
of  any  of  the  organs  is  encroached  upon  by  disease  or 
faulty  habits  of  living.  In  disordered  states  of  the  ner- 
vous system,  especially  where,  in  the  history  of  the  indi- 
vidual, there  is  the  least  intimation  of  manic-depressive 
or  other  form  of  insanity,  extreme  care  should  be  taken 
in  recommending  sea  journeys,  if  disastrous  consequences 
are  to  be  averted. 

The  number  of  suicides  committed  at  sea,  and  the 
carelessness  with  which  unfortunates  suffering  from  sea- 
sickness are  treated  is  a  disgrace  to  civilized  humanity. 
The  lonely  individual  suffering  inner  torments,  as  the 
result  of  repeated  labyrinthine  irritations,  wanders  about 
in  a  state  of  mental  agony,  not  knowing  what  is  the  mat- 
ter with  him,  nor  how  to  properly  orient  himself  in  the 
whirl  of  his  disordered  imaginings.  Instead  of  receiving 
proper  medical  treatment  which  would  include  close 
supervision,  and  a  goodly  amount  of  reassurance,  such  an 
individual  is  left  severely  alone,  with  the  result  that 
relief  from  mental  distress  of  purely  artificial  origin  is 
sought  in  self-destruction. 

Although  much  has  been  done  in  recent  years  to  im- 
prove the  general  conditions  of  travelling  at  sea,  jret  very 


SEASICKNESS  515 

little  has  been  done  to  alleviate  the  distress  of  those 
suffering  from  seasickness.  The  blame  for  this  does 
not  perhaps  wholly  lie  at  the  door  of  the  ship-owners, 
since  so  little  has  been  hitherto  definitely  understood 
about  the  malady.  However,  the  fact  remains  that  the 
hospital  on  ship  board  is  generally  located  in  the  stem, 
over  the  propeller,  where  the  motions  of  the  boat  have  the 
most  sickening  effect  and  where  the  jolting  of  the  ma- 
chinery is  a  constant  cause  of  continued  distress.  The 
sick  and  suffering  are  committed  to  such  quarters  when 
their  condition  has  become  extreme.  Moreover,  one 
physician  can  hardly  be  expected  to  properly  look  after 
the  needs  of  two  or  three  thousand  persons.  In  addition 
ship  surgeons  should  receive  special  training  so  as  to 
thoroughly  understand  the  effects  of  seasickness  upon  the 
physiological  economy,  that  they  may  be  enabled  to  treat 
intelligently  not  only  seasickness,  but  all  other  illnesses 
that  may  arise  during  a  voyage.  Medical  colleges  also 
should  give  instruction  on  this  subject  which  is,  at  least, 
as  important  to  the  general  medical  man  as  ' '  insurance 
examination"  and  other  subjects  at  present  receiving 
special  attention. 

It  seems  strange  that  in  this  age  of  magnificent  philan- 
thropy, no  one  has  seen  fit  to  inquire  into  this  matter, 
with  a  view  to  improving  the  hospital  facilities  on  ocean 
liners  and  the  quantitative  and  qualitative  efficiency  of 
the  medical  attendants.  At  the  present  time,  perhaps,  no 
other  field  offers  such  great  opportunities  for  the  relief  of 
human  suffering  and  the  promotion,  on  a  large  scale,  of 
the  comfort  of  the  many  both  rich  and  poor  alike. 

The  possibility  of  seasickness  resulting  in  subacute 
or  chronic  impairment  of  the  digestive  functions  and 
even  in  chronic  inflammatory  conditions  of  the  gastric 
mucosa  has  been  referred  to  in  a  previous  chapter.  The 
extreme  degree  of  protracted  congestion  of  the  abdominal 
viscera  undoubtedly  may  cause  a  predisposition  to  vary- 
ing grades  of  inflammation  not  only  in  the  stomach,  but 
also  in  other  organs.  It  is  very  probable  that  prolonged 
congestion  of  the  ovaries  is  an  important  factor  in  caus- 
ing the  amenorrhoea  that  follows  seasickness. 

The  effect  of  seasickness  upon  the  ner^'ous  system 
often  manifests  itself  in  disturbances  in  the  growth  and 


516  SEASICKNESS 

nutrition  of  the  hair  which  often  tends  to  fall  out  during 
a  voyage  and  frequently  remains  sickly  and  "unman- 
ageable" for  some  time  after  the  journey  has  ended.  The 
general  effect  upon  the  nervous  system  is  also  reflected  in 
the  obstinate  constipation  which,  however,  involves  other 
factors  such  as  deprivation  of  food,  failure  of  gastro-intes- 
tinal  motility,  etc.  During  the  height  of  an  attack  of  sea- 
sickness the  urine  is  also  diminished  and  concentrated, 
due  in  part,  to  deprivation  of  liquids,  failure  of  absorp- 
tion or  both,  and  in  part  to  disturbance  of  the  nervous 
and  circulatory  mechanisms. 

It  has  been  frequently  stated  that  "colds"  are  an  un- 
usual thing  at  sea.  Barker  ^39  states  that  he  has  known 
them  to  have  occurred.  It  is  a  fact,  however,  that  they 
are  unusual.  Subject  "B"  of  these  studies  has  never 
"caught  cold"  at  sea,  although  it  has  been  his  custom  to 
sit  on  deck  without  extra  clothing  in  all  sorts  of  weather. 
Indeed  it  has  been  his  experience  that  if  he  "had  a  cold" 
going  on  board,  it  rapidly  disappeared  in  a  short  time 
after  putting  out  to  sea. 

One  thing  should  always  be  remembered  by  those 
whose  means  do  not  permit  them  to  travel  in  a  separate 
stateroom,  and  that  is,  that  contact  is  usually  very  close 
between  the  occupants  of  the  same  cabin,  so  that  if  one 
occupant  is  affected  with  a  communicable  disease,  the 
others  may  possibly  become  infected.  At  the  present 
time  quarantine  supervision  is  so  strict,  and  the  laity 
know  so  much  about  disease,  that  infection  occurring  in 
this  way  must  be  exceedingly  rare,  and  yet  first-hand 
evidence  convinces  us  that  there  is  such  a  possibility.  As 
late  as  the  autumn  of  1906  a  gentleman  in  a  hurry  to  get 
back  to  the  United  States  found  it  difficult  to  procure 
accommodation  in  the  first  class.  He  telegraphed  to 
various  lines,  and  finally  was  pleased  to  learn  that  a  cer- 
tain line  had  a  vacancy  which  he  immediately  secured. 
On  the  first  night  out  at  sea,  he  found  the  cabin  small 
and  occupied  by  four  full-grown  men.  One  of  the  occu- 
pants coughed  all  night  so  that  sleep  was  impossible 
except  in  snatches.  This  annoyance  was  borne  in  a 
good-natured  way  ]:)y  the  occupants  of  the  cabin,  but  early 
daylight  revealed  the  uncomfortable  fact  that  the  indi- 
vidual with  the  cough  was  an  undoubted  victim  of  pul- 


SEASICKNESS  517 

monary  tuberculosis,  and  what  was  still  worse,  that  he 
acted  as  though  he  was  utterly  unaware  that  he  was  a 
menace  to  his  fellow  room-mates.  Application  was 
quietly  made  to  the  purser  but  without  redress.  The  cap- 
tain was  then  approached,  and  to  his  credit  be  it  said 
that  he  did  everything  in  his  power  to  relieve  the  situa- 
tion. The  hospital  was  placed  at  our  American  friend's 
disposal,  but  as  he  was  very  prone  to  seasickness  he 
feared  the  excessive  motion  and  the  vibration  from  the 
machinery,  for  the  hospital  was  located  just  above  the 
propeller.  The  printers'  room  was  next  suggested.  In- 
vestigation showed  a  state  of  affairs  that  precluded  it 
from  acceptance.  Finally  with  the  aid  of  the  ship's  car- 
penter a  bed  was  arranged  over  a  bath-tub  in  a  clean, 
wholesome  bathroom.  During  the  remainder  of  the  voy- 
age, the  sick  man  coughed  and  coughed,  and  apparently 
never  made  the  slightest  attempt  to  intercept  his  column 
of  spray  at  times  painfully  visible  in  the  light  that 
streamed  from  the  port-hole.  His  two  roommates  had  to 
make  the  most  of  the  situation,  although  one  of  them  was 
fully  aware  of  the  danger,  for  he  himself  had  been  a  vic- 
tim of  tuberculosis,  and  was  then  actually  returning  from 
a  protracted  sojourn  on  the  Italian  Kiviera,  whither  he 
had  gone  to  rid  himself  of  the  disease.  Another  impor- 
tant fact  is  that  this  tuberculosis  victim,  the  one  who 
coughed  constantly,  was  a  steady  reader.  Book  after 
book  came  to  him  from  the  ship's  library  to  be  thumbed 
and  coughed  upon  from  cover  to  cover.  This  should  sup- 
ply food  for  thought  for  travellers  accustomed  to  delving 
into  the  volumes  of  the  ship's  library.  It  may  be  true 
that  colds  are  unusual  at  sea,  but  close  contact  for  whole 
nights  in  small  stuffy  cabins  with  closed  port-holes, 
backed  by  the  depression  and  exhaustion  that  accompany 
seasickness,  render  infection  an  easy  matter  under  such 
conditions  as  those  just  related. 


CHAPTER  XXXV 

HOW   RECOVERY  FROM  SEASICKNESS  TAKES  PLACE. 
OUTLINES   OF   TREATMENT 

The  manner  in  which  recovery  from  seasickness  takes 
place,  merely  illustrates  the  wonderful  adaptability  of  the 
organism  to  circumstances  and  conditions.  The  cerebral 
cerebellar  and  medullary  centres  become  accustomed  to 
the  degree  and  rhythmicity  of  the  labyrinthine  stimuli  to 
such  an  extent  that  the  cerebral  centres  are  no  longer 
preoccupied  and  perturbed  by  the  unaccustomed  irregu- 
lar activities  of  the  cerebellar  functions  of  equilibration 
and  cease  to  hamper  the  latter  by  attempts  at  compensa- 
tion, thereby  permitting  the  cerebellar  mechanisms  to 
readjust  themselves  to  the  new  conditions.  The  medul- 
lary centres,  having  somewhat  recovered  from  the  surprise 
of  unaccustomed  stimuli,  proceed  with  the  business  of 
carrying  out  their  proper  functions  regardless  of  afferent 
labyrinthine  impressions  of  the  particular  degree  and 
rhythmicity  experienced.  Recovery  does  not  take  place 
by  the  labyrinthine  receptors  becoming  "accustomed  to 
the  motions  of  the  endolymph"  as  some  authors  assert. 
It  is  in  the  nervous  centres  that  the  readjustments  take 
place  which  are  responsible  for  the  recovery,  just  as  it  is 
in  the  centres  and  not  at  the  periphery  linger  those 
impressions  which  are  responsible  for  the  existence  of 
sea-legs  upon  shore  for  many  days  after  a  voyage  has 
ended. 

In  seasickness  as  in  other  ailments,  the  great  desid- 
eratum of  the  profession  and  laity  is  the  prophylaxis. 
From  the  experiments  and  observations  set  forth  in  these 
pages  and  from  an  extensive  experience  with  the  malady 
at  close  range,  it  is  safe  to  assert  that  seasickness  can,  in 
most  instances,  be  effectively  prevented  by  the  adoption  of 
judicious  measures,  supported  in  certain  cases  by  the  use 

518 


SEASICKNESS  519 

of  certain  drugs  administered  with  proper  precaution  as 
to  time,  dosage,  age  of  the  patient,  etc.  Healthy  indi- 
viduals might  perhaps  be  permitted  to  procure  and  use 
such  drugs,  but  the  practice  is  not  in  all  cases  to  be  recom- 
mended, the  chief  reason  being  that  in  certain  diseased 
conditions  of  the  organs  and  in  certain  phases  of  seasick- 
ness drugs  and  circulatory  stimulants  of  any  kind  may  be 
contraindicated. 

Theoretically,  the  first  indication  in  the  prophylaxis 
is,  of  course,  to  lower  the  irritability  of  the  labyrinthine 
nerve  terminals  or  of  the  vestibulo-cerebellar  mechanisms. 
It  must  be  confessed  that  in  the  trials  made  thus  far,  no 
safe  drug  has  been  found  to  meet  this  indication.  More- 
over physiological  considerations  lead  to  the  belief  that 
such  a  drug,  if  found,  might  be  of  doubtful  benefit  as  a 
pure  preventative,  however  it  might  otherwise  help  in  the 
actual  treatment  of  seasickness.  Failing  to  prevent  those 
irritations  of  the  labyrinthine  receptors  the  next  indica- 
tion is  to  prevent  their  pernicious  effects  upon  the  cere- 
bellar, medullary,  and  cerebral  centres.  Here  many 
measures  are  available  including  general  hygienic  meas- 
ures preparatory  to  the  voyage,  mental  quiet,  attention  to 
the  gastrointestinal  functions  and  the  employment  of 
drugs,  especially  atropin  or  hyoscyamin  preferably  by  hy- 
podermic administration.  These  drugs,  however,  should 
not  be  used  indiscriminately  nor  continuously.  Bro- 
mides have  little  to  recommend  them.  The  use  of  co- 
cain  is  contraindicated.  Clinical  and  experimental  re- 
sults obtained  in  seasickness  and  in  rotation  sickness, 
and  the  peculiar  effects  produced  by  the  drug  upon  ani- 
mals in  which  it  causes  manege  (circus)  movements,  lead 
to  the  belief  that  cocain  predisposes  the  organism  to  sea- 
sickness. In  one  instance  at  least  the  administration  of 
cocain  by  a  dentist  has  led  to  all  the  phenomena  pecul- 
iar to  profound  labyrinthine  disturbance  (Koenig228). 
The  size,  location,  and  ventilation  of  the  cabin  or  suite 
has  an  important  bearing  in  prophylaxis.  The  avoidance 
of  hurry  previous  to  going  on  board  and  congenial  adapta- 
tion to  the  new  environment,  are  a  distinct  help  in  preven- 
tion, whilst  rest  in  recumbency  has  been  justly  advocated 
in  all  times.  Light  and  easily  digested  food,  taken  in 
paoderation,  anci  under  conditions  most  favoiirable  to 


520  SEASICKNESS 

digestion,  is  of  benefit.  Hypnotic  suggestion  as  a  pre- 
ventati  v^e  and  even  as  a  means  of  treatment  of  a  present 
attiick  has  been  tried  with  varj^ing  success.  Beard  ^^ 
believed  that  it  could  prevent  rotation  sickness.  Experi- 
ence with  hypnotism  in  the  experiments  in  rotation,  and 
aural  irrigations  shows  conclusively  the  limited  benefit 
that  is  to  be  expected  from  suggestion  in  these  conditions 
and  in  true  (somatic)  seasickness.  Where  the  psychic 
factor  predominates,  or  seems  to  be  the  chief  source  of 
distress,  hypnotism  is  of  undoubted  benefit;  but  where 
the  condition  is  one  of  true  (somatic)  seasickness  caused 
by  labyrinthine  irritation  little  can  be  expected  from 
hypnotic  suggestion  beyond  the  alleviation,  to  a  certain 
extent,  of  disturbances  arising  from  some  of  the  secondary 
sources  of  irritation.  In  this  respect,  therefore,  hypno- 
tism has  a  value  in  true  seasickness  that  puts  it  on  a  par 
with  the  thousand  and  one  remedies  that  have  been  put 
forward  by  writers  from  time  immemorial  as  sure  and 
certain  cures.  It  is,  however,  very  questionable  whether 
the  influence  of  post-hypnotic  suggestion  would  continue 
sufficiently  long  even  in  cases  of  so-called  psychic  nau- 
pathia  to  be  of  lasting  benefit.  Hence  it  would  be  neces- 
sary to  have  the  individual  hypnotized  again  and  again  at 
frequent  intervals  and  the  suggestions  repeated.  These 
and  like  considerations  lead  to  the  conclusion  that  hypno- 
tism has  a  limited  field  of  usefulness  in  seasickness,  and 
that  it  is  perhaps  a  therapeutic  resource  which  should  be 
reserved  to  meet  certain  indications  only.  This  does  not 
mean,  however,  that  ordinary  methods  of  suggestion 
should  not  be  utilized  to  brighten  and  enliven  prospective 
and  actual  travellers.  Suggestion  is  a  potent  means  of 
breaking  up  the  vicious  train  of  secondary  psychic 
phenomena  and  should  be  made  the  most  of  under  all 
conditions  and  at  all  times. 

Various  devices  have  been  employed  to  prevent  sea- 
sickness. Swinging  beds  have  been  used,  but  evidently 
little  benefit  was  obtained,  for  their  use  has  been  aban- 
doned. Since  the  introduction  of  the  mono-rail  system 
of  railway,  various  suggestions  have  been  made  to  apply 
the  principle  of  the  gyroscope  so  as  to  obviate  the  rolling 
motions  of  ships  at  sea  and  thereby  to  prevent  seasick- 
ness.    It  is  difficult  to  see  in  what  wa^  such  a  thing  could 


SEASICKNESS  521 

be  effected  so  as  to  restrain  all  the  movements  of  a  ship, 
but  stranger  things  have  come  to  pass,  and  one  never 
really  knows  what  can  be  done  until  some  genuine  attempt 
is  made. 

The  treatment  of  an  actual  attack  of  seasickness  re- 
solves itself  into  combating  the  effects  of  primary  labyrin- 
thine irritations  upon  the  cerebellar,  medullary  and  cere- 
bral centres  and  in  eliminating,  as  far  as  possible,  all 
secondary  sources  of  irritation.  In  most  cases  seasick- 
ness is  protracted  and  aggravated  by  bad  management. 

Atropin,  given  preferably  hypodermically,  has  been 
found  to  counteract  the  psychic  depression  that  accom- 
panies seasickness.  In  addition,  by  its  action  in  depress- 
ing the  sensory  nerve  terminals  all  over  the  body,  and 
especially  in  the  stomach  and  intestine,  it  effectively 
cuts  off  afferent  irritating  impulses  w^hich  are  such  promi- 
nent secondary  sources  of  distress.  By  its  well-known 
action  upon  the  medullary  centres  atropin  can  be  of 
wonderful  service  in  regulating  to  a  certain  extent,  some 
of  the  circulatory  disturbances  incidental  to  seasickness, 
but  the  observations  on  the  circulation,  as  shown  in  the 
protocols,  indicate  that  in  protracted  voyages  and  where 
vaso-motor  exhaustion  has  already  set  in,  atropin  or  any 
method  of  stimulation  has  to  be  used  with  caution. 

The  stomach  is  the  most  important  of  the  secondary 
sources  of  irritation  in  seasickness.  The  care  of  this 
organ  in  seasickness  differs  in  no  wise  from  the  care  that 
should  be  accorded  it  in  conditions  of  acute  or  subacute 
gastritis  on  shore.  It  has  been  shown  that  an  extreme 
degree  of  congestion  of  the  gastric  mucous  membrane  is 
present  in  seasickness,  hence  the  stomach-tube  should  not 
be  used  at  all,  or  used  only  with  extreme  caution.  The 
liberal  blood-supply  of  the  gastric  submucosa  and  the 
existence  of  the  oesophageal  plexus  of  veins  should  be 
remembered.  Slight  trauma  in  these  regions  has  been 
followed  by  fatal  hemorrhage,  and  fatal  gastric  hemor- 
rhage has  been  known  to  occur  in  seasickness  and  other 
conditions  in  w^hich  violent  vomiting  occurs.  Hence  if 
the  stomach  needs  to  be  washed  out  it  is  best  to  have  the 
patient  drink  warm  water  with  some  hannless  alkali 
(bicarbonate  of  soda)  dissolved  in  it.  This  solution  helps 
to  separate  the  masses  of  mucus  from  the  gastric  walls^ 


522  SEASICKNESS 

and  it  is  readily  vomited.  During  the  acute  stages  of 
gastric  irritation  food  of  every  kind  is  contraindicated  for 
a  short  period.  Later  on  liquid  nourishment  may  be 
given  tentatively.  It  is  important  to  get  the  patient  to 
take  food  as  early  as  practicable,  and  of  the  different  food- 
stuffs the  first  preference  should  be  given  to  some  digesti- 
ble form  of  the  carbohydrates.  The  absence  or  reduction 
of  free  HCl  noted  in  the  analyses  of  the  various  test 
meals,  renders  it  inadvisable  to  give  meat  in  any  quan- 
tity, until  the  stomach  functions  are  fairly  reestablished. 

In  certain  conditions  extracts  of  the  gastric  mucosa 
or  meat-extracts  such  as  beef-tea,  etc.,  will  find  indica- 
tion. These  extracts  may  be  given  ^^er  os  or  p&r  recUim. 
It  is  not  advisable  to  administer  them  intravenously  or  by 
hypodermoclysis,  as  in  the  author's  experimental  trials 
the  subjects  were  invariably  affected  with  fever  and  symp- 
toms similar  to  those  of  serum  sickness.  Undoubtedly 
in  many  instances  the  extracts  may  do  good,  especially  in 
conjunction  with  atropin  and  strychnin  in  grave  cases, 
both  on  sea  and  land,  where  the  restoration  of  gastric  and 
intestinal  function  is  urgently  demanded.  It  is  to  be 
added,  however,  that  in  some  of  the  tests  in  which  atro- 
pin had  not  been  previously  administered  the  extracts 
seemed  to  add  to  the  irritability  of  the  gastric  mucosa 
aggravating  the  subject's  distress. 

Constipation  may  be  obviated  by  a  judicious  use  of 
cathartics  in  ordinary  cases.  The  hormones  (peristaltic 
hormone  of  Zuelzer)  have  been  used  on  shore  for  the 
relief  of  constipation  in  various  conditions  (Zuelzer, ^^s 
Saar,287  Unger,^^^  and  others)  and  much  is  to  be  hoped 
from  their  use  in  seasickness,  especially  when  combined 
with  the  other  measures  recommended,  viz.,  atropin, 
etc.  It  is  earnestly  to  be  hoped  that  some  preparation  of 
secreting  hormone  adapted  to  hypodermic  or  intramus- 
cular administration,  will  be  forthcoming  soon,  as  the 
author's  experiments  have  led  him  to  believe  that  the 
hormones  will  prove  a  decided  help  in  the  treatment  of 
severe  cases  of  seasickness. 

Disordered  circulation  is  another  great  secondary 
source  of  irritation  in  seasickness.  In  order  to  meet 
properly  the  indications  under  this  head,  frequent  ob- 
servations  of   the   pulse   and   blood-pressure   should  be 


SEASICKNESS  523 

made.  The  physician  should  thoroughly  understand  the 
peculiarities  of  the  individual's  circulatory  mechanisms. 
In  any  individual  over  forty,  and  in  persons  who  have 
been  a  hon  vivants  all  their  lives,  the  greatest  care  has  to 
be  taken  to  avoid  injury  to  the  cardiac  musculature. 
Such  individuals  should  not,  under  any  circmnstances, 
undertake  a  journey  upon  the  seas,  without  consulting 
their  physicians  on  shore,  who  should  carefully  instruct 
them  regarding  matters  calculated  to  affect  the  present  or 
future  efficiency  of  the  heart.  Rest  in  bed  may  be  the  in- 
dication when  the  circulatory  function  has  been  carefully 
studied.  The  patient  may  chafe  at  this,  but  in  common 
honesty  he  should  be  instructed  as  to  the  consequences. 
Few  individuals  would  be  willing  to  barter  years  of 
health  and  efficiency  for  the  gratification  of  going  upon 
deck  to  show  what  good  sailors  they  are.  And  yet  that 
this  must  be  a  matter  of  frequent  occurrence  may  be 
readily  deduced  from  a  careful  study  of  the  figures  given 
in  the  protocols.  As  before  stated,  the  conser^'ation  of 
the  individual's  health  in  regard  to  this  matter  rests  in  a 
great  measure  upon  the  instructions  given  by  the  medical 
adviser  on  shore.  As  the  circulation  improves  measures 
calculated  to  benefit  the  general  condition  may  be  em- 
ployed with  care.  Cold  bathing  should  always  be  pro- 
hibited until  a  study  of  the  circuJation  shows  that  it  is 
permissible.  The  same  has  to  be  said  of  exercise  and  of 
any  remedy  that  tends  to  stimulate  the  cardio-vascular 
apparatus.  So  long  as  there  is  evidence  of  exhaustion  in 
the  neuro-vascular  mechanisms,  circulatory  and  vaso- 
motor stimulants  are  contraindicated.  Fresh  air  is 
always  of  importance,  though  this  does  not  necessarily 
imply  that  the  patient  is  to  have  a  cold  air  bath.  The 
protocols  show  what  a  depressing  effect  upon  the  neuro- 
vascular apparatus  a  hot  cabin  may  have,  and  where  the 
object  is  to  prevent  strain  and  injury  to  the  heart,  the 
temperature  of  the  cabin  should  be  regulated  as  far  as 
possible,  and  by  artificial  means  if  necessary. 

The  other  sources  of  secondary  irritation  in  seasick- 
ness are  the  eyes,  the  ears,  the  olfactor}^  organs,  the 
psychic  cerebral  areas,  the  spinal  cord,  and  the  general 
peripheral  sensoiy  terminations.  In  the  condition  to 
which  seasickness  may  reduce  any  individual,  the  active 


524  SEASICKNESS 

functioning  of  any  of  these  organs  may  be  a  source  of 
depression  and  distress.  Thus  the  prolonged  use  of  the 
eyes  is  to  be  forbidden  as  in  reading  steadily.  Noises 
also  should  be  suppressed.  Offensive  odours  are  to  be 
avoided,  and  this  makes  one  wonder  why  gentlemen  will 
smoke  on  deck  where  the  odour  they  create  sends  shivers 
down  the  spines  of  delicate,  suffering  women.  Anything 
that  tends  to  unduly  arouse  the  emotions,  or  to  evoke  a 
prolonged  train  of  serious  thought  should  be  avoided. 
The  brain  should  be  rested  as  much  as  possible,  and  the 
individual  placed  in  the  most  agreeable  and  inexacting 
surroundings.  It  frequently  happens  that  in  certain 
stages  of  seasickness  the  sexual  desire  is  exalted  out  of 
proportion  to  the  actual  power  of  the  individual.  Under 
such  circumstances  attempts  at  intercourse  should  be 
prohibited. 

From  the  results  obtained  in  rotation  sickness,  the 
conclusion  was  reached  that  hyoscin  should  never  be 
iised  in  seasickness.  Morphin  was  also  found  to  have 
disagreeable  effects  notwithstanding  its  effect  in  enhanc- 
ing the  circulatory  function.  Any  drug  or  remedy  that 
tends  to  depress  the  medullary  centres  should  be  avoided 
in  seasickness  and  those  drugs  and  measures  which  tend 
to  stimulate  these  centres  must  be  used  with  caution  and 
with  due  respect  to  the  condition  of  the  centres  at  the 
time,  i.e.,  whether  they  are  in  a  state  of  exhaustion  from 
overirritation  or  merely  in  a  state  of  lethargic  inactivity. 

The  gyroscope  has  been  mentioned  as  a  possible  means 
of  preventing  seasickness  by  restraining  the  movements 
of  the  ship  as  a  whole.  In  the  actual  treatment  of  sea- 
sickness or  of  any  serious  illness  at  sea,  the  principle  of 
the  gyroscope  might  be  applied  in  conjunction  with  a 
swinging  deck  or  compartment.  Thus,  for  instance,  a 
swinging  hospital  steadied  by  revolving  fly  wheels,  might 
be  maintained  on  every  large  steamer  for  those  who  may 
be  dangerously  ill.  Such  a  contrivance  if  practicable, 
would  also  render  surgical  procedures  at  sea  much  safer 
than  they  are  at  present  and  would  aid  convalescence  ma- 
terially besides  reducing  the  patients'  suffering  to  a  mini- 
mum. Recently,  a  systf;mof  U  tubes  or  tanks  devised  by 
Frahm  has  been  tried  on  some  of  the  ships  in  the  German 
navy.     The  reports  indicate  that  the  rolling  of  the  vessels 


SEASICKNESS  525 

was  considerably  reduced.  Whether  the  use  of  such  tubes 
will  prove  effective  in  preventing  seasickness  is  a  matter 
for  further  research.  Such  devices  need  not  necessarily 
com]3letely  stop  all  rolling  or  movement  of  the  boat,  as  it 
will  materially  aid  sufferers  at  sea  if  the  sudden  stops 
and  starts  in  the  ship's  movements  be  eliminated  or  even 
partially  restrained. 


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256.  Binz,   Ueber  die  Seekrankheit.     Centralblatt  fiir  Innere 

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258.  Van  Trostenburg,  Die  Seekrankheit  und  ihre  Verhiitung. 

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259.  Koepke,  Therapeutische  Monat.     June,  1904. 

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INDEX    TO    THE    SEMICIRCULAR 
CANALS 


Abdominal  and  pelvic  viscera, 
fibres  for  blood-vessels 
of,  100 

Abdominal  viscera,  congestion 
of,  177 
severance  of,  from  spinal 
cord,  103 

Abducens  centre,  20 

Abducens  nucleus,  fibres  from, 
49 

Abducent  nucleus,  fibres  to, 
40 

Absorption,  controlled  by  local 
mechanisms,  174 
experiments,  173 
of  food,  active,  234 
tests  for,  176,  189 

Accelerator  centre,  location 
of,  102 

Accelerator  fibres  for  the 
heart,  102 

Accessory  acoustic  nucleus,  14 

Accessory  nerve  (the  elev- 
enth), a  motor  nerve,  35 

Accessory  olivary  nuclei,  con- 
nections of,  56 

Accommodation  constriction, 
110 

Accommodation  synkinesis, 
110 

Acoustic  area,  elements  of,  9 

Acoustic  nucleus,  constitution 
of,  14 

Acoustic     striae,     component 
fibres  of  the,  16 
fibres  from  the,  53 

Afferent  cochlear  fibres,  20 

Afferent  and  efferent  im- 
pulses, relay  station  for, 
41 


Afferent  paths,  45,  46,  51,  52, 
53   54,  56,  59,  60,  62,  67, 
68,  72,  73 
peripheral  terminations  of 
the,  83-94 

A  f  t  e  r-nystagmus,    apparent 
movements    of    objects 
during,  262,  267,  274 
horizontal,  276,  277,  279 
premature  induction  of  the 
natural,  195,  204,  205 

Ampulla,  of  the  superior  ca- 
nal, irritation  of,  5 
of    the    posterior    canal, 
5,6 

Ampullary  receptors,  muscu- 
lar associations  of,  281, 
282 

Anaesthesia,  recovery  from, 
317 

Anatomical  connections,  sy- 
nopsis of,  40-77 

Anelectrotonus,  state  of,  280 

Angnlar  gyrus,  left,  78 

Animal  experimentation,  265 

Animals  live  after  severance 
of  abdominal  viscera 
from  spinal  cord,  103 

Anode  tests,  270,  271 

Ansa  lenticularis,  position  of, 
64 

Ansa  peduncularis,  position 
pf,    64 

Anterior  nerve-roots,  connec- 
tions of,  100 

Apertura  externa  aquasductus, 
position  of,  4 

Aqueduct  of  Sylvius,  grey 
matter  of,  69 

Aquaeductus  vestibuli,  7,  37 


537 


538 


INDEX 


Arcuate  fibres,   anterior   and 
posterior  superficial,  43 
Arcuate  nucleus,  fibres  of,  44 
Arterial  relaxation,  shock  due 

to,  134 

Arterial   tension,  nature's 

methods    in    combating- 

lowered,  135 

Arterio-sclerosis,  general,  246 

Association  fibres,  division  of, 

74 
Atropin,  effect  of,  in  relieving 
stomach  discomfort,  189 
action  of,  on  the  cerebral 
psychic  and  motor  areas, 
189,  190 
influence  of,  in  rotations, 
134 
Auditory  area,  stimulation  of, 
in  the  temporal  lobe,  15 
Auditory    canal,    cold   irriga- 
tions   of    the   external, 
245 
effects   of   irrigations    of 

the  external,  207 
internal,       relations      of 

nerves  in,  12 
sensory  stimulation  of  the 
external,  248 
Auditory  nerve,  elective  vul- 
nerability   of    cochlear 
branch  of,  38 
Auerbach's  plexus,   cells  and 

fibres  of,  165 
Auer's    experiments    on    the 

splanchnics,  169 
Aural    irrigations,    cause    of 
nystagmus  in,  243 
disturbances  of  coordina- 
tion accompanying,  248 
effects  of,  181 
effects  of,  upon  the  eyes, 

250 
effects  of,  upon  the  diges- 
tive apparatus,  233-249 
effects  of,  upon  equilibra- 
tion, 237 
rise  of  blood-pressure   in, 

243 
general  effects  of,  207-219 
mechanism  of,  288 
phenomena  of,  219,  247 


Aural  irrigations,  possible  aid 
in     the    treatment     of 
nerve  deafness,  249 
pylorus  tightly  closed  iDg 
235 

Autophony,  246 


Bahnung,  mutual  reinforce- 
ment of  impulses,  177, 
179,  180 
Bannister's  researches  and  ex- 
periments on  the  semi- 
circular canals,  125 
Bilateral  cortical  innervation, 

31 
Bilateral  hot  irrigations,  244 
Bilateral  irrigation,  275,  279 
Bipolar  neurones,  13 
Blood-pressure,     changes    in, 
during  irrigations,  255 
effect    of    strychnin    and 
atropin  in   maintaining 
the,  134 
lowering  of  the,  102 
mechanism    which    regu- 
lates the,  133 
raised    by    vaso-constric- 

tion,  133 
rise   of,    in   aural   irriga- 
tions, 243 
threatened    dissolution 
from  fall  of,  134 
Blood-supply  of  the  labyrinth 
and  of  the  cranial   nu- 
clei, 37-39 
Blood-vessels,  contraction  and 
dilation  of,  131 
disease  of,  248 
fibres  for,  100 
Blood,  vomiting  of,   in  aural 

irrigations,  233 
Bogen-commissure  of  Stilling, 

70 
Bowels,    uneasiness    of    the, 

during  rotations,  181 
Brain,     medullary    substance 
of,  74 
sensory  paths  of,  72 
vascular   supply   of    base 
of,  39 
Breuer's  suction,  267 


INDEX 


539 


Bronchial  musculature,  motor 

fibres  for,  101 
Bulbar  autonomics,  31 

Cajal,  tract  from  the  inter- 
stitial nucleus  of,  86,  87, 

Calcarine  fissure,  78 

Canaliculi  cochleas,  venous 
blood-draining-  into,  37 

Canalis  reuniens,  location  of,  7 

Carbohydrates,  acid  hindrance 
to  digestion  of,  175 

Cardiac  acceleration,  102 

Cardiac   arhythmia,    in    rota- 
tions, 135 

Cardiac  fibres,  inhibitory,  ori- 
gin of,  34 

Cardiac  mechanism,  sensitive- 
ness of  the,  135 

Catalepsy  in  the  standing  po- 
sition, 216 

Cataleptic  rigidity,  state  of, 
217 

Cathode  tests,  270,  272 

Cats,    Ferrier's    experiments 
on,  293 
Parson's  experiments  on, 

112 
stimulation  of  cerebellum 
of.  291 

Caudate  nuclei,  fibres  of,  63 

Caudate  nucleus,  fibres  from, 
67 

Cells  of  chief  nucleus,  disltf 
cated  groups  of,  23 

Central    nervous   system,    di- 
vision of,  90 
continuity  of,  98 
efferent  paths   from   the, 
99 

Cerebellar  areas,  Ferrier's  ex- 
periments on  stimulat- 
ing, 302 

Cerebellar  connections,  43-44 

Cerebellar  cortex,  fibres  from, 
54 

Cerebellar  hemisphere,  rela- 
tions of,  114 

Cerebellar  mechanisms,  activ- 
ity of,  116,  302 
efferent  limbs  of,  303 
and  migraine,  336 


Cerebellar    mechanisms    and 
neurasthenias  of  various 
forms,  336 
Cerebellar  paths,   recapitula- 
tion of  the,  94-97 
Cerebellar     superior    olivary 
tract,  an  efferent  cere- 
bellar path    for  ocular 
movements,  26 
Cerebellar    tonus,    depression 

of,  261 
Cerebello-cortical  circuit,  dis- 
turbance of,  311 
Cerebello-superior    olivary 

tract,  fibres  of,  57 
Cerebello-tegmental    tract, 

fibres  of,  47 
Cerebellum,     connections     of 
the,  through  rubro-spinal 
tract,  47 
connections  of  the,  through 
the  middle  peduncle,  45- 
49 
diagrams  showing  the  ef- 
fects of  various  opera- 
tions upon,  324,  325 
electrical  stimulation   of, 

289 
extirpation  of  lateral  lobe 

of,  323 
Ferrier's  stimulation  ex- 
periments on  the,  115 
fibres  from  the,  56 
fibres  passing  to  the,  34 
paths  of  the,  26 
pupillary  centres  in,  260 
relation    of  the,    to    spe- 
cialized sensory  organs 
of  equilibration,  115 
stimulation  "of  various 

parts  of  the,  290,  291 
transmitting  afferent  im- 
pulses to  the,  19 
unilateral  lesions  of  the, 
326 
Cerebral  apoplexy,  turning  of 

eyes  in,  116 
Cerebral  centres,  direct  tonus 

influence  of,  115,  116 
Cerebral   cortex,   auditory 
paths  of,  16 
fibres  from,  53 


540 


INDEX 


Cerebral  cortex,  ocular  move- 
ments in,  294 
removal  of  areas  of,  323 

Cerebral  hemorrhage,  confined 
to  one  hemisphere,  116 
conjugate  deviation  in,  312 

Cerebral  motor  cortex,  81 

Cerebral  ocular  area,  effect  of 
removal  of,  322 

Cerebral     peduncle,     arteries 
supplying,  39 

Cerebral  synkinesis,  phenom- 
enon of.  111 

Cervical  sympathetic,    stimu- 
lation of,  257 

Chorda  tympani,  30 

taste  fibres  of  the,  30 

Circulatory  depression,  134 
vomiting  in  severe  states 
of,  167 

Ciliary    ganglion,    nature    of 

I  cells  in,  107 

f        removal  of,  107 

Clarke's     column,     vesicular 
cells  of,  34,  35,  81 

Cochlear  artery,  37 

Cochlear     fibres,     description 
of,  13,  14 

Cochlear    ganglion,    ganglion 
cells  of  the,  38 

Cochlear  nerve,  disease  of,  246 

Commissura      hypothalamica, 
fibres  of,  49,  QS 

Commissura  posterior  cerebri, 
66 

Commissural  tracts,  58 

Commissure  of  Meynert,  fibres 
through,  50 

Conceptualization    and    hear- 
ing, 78 

Conjunctiva  of  both  eyes,  con- 
gestion of,  250 

Connections  of  the  cerebellum, 
43-44 
of  the  cerebellum,  through 
the  middle  peduncle,  45 
of  the  cerebellum,  through 
the    superior    peduncle, 
46 
of  the  corpus  striatum,  73 
of  the  corpus  subthalami- 
cumj  67 


Connections    of    the    inferior 
colliculi,  53 
of  the  inferior  olivary  nu- 
cleus, 54 
of  the  lateral  fillet  or  lem- 
niscus lateralis,  52 
of  the   lateral  geniculate 

body,  52 
of  the  mammillary  nucle- 
us, 68 
of  the  median  geniculate 

bodies,  54 
of  the  mesial  fillet  or  lem- 
niscus, 49 
of  the  optic  thalamus,  62 
of  the  pontine  nucleus,  60 
of  the  red  nucleus,  60 
of  the  rhinencephalon,  72 
of    the    substantia  nigra, 

67 
of  the  superior  colliculi  of 
the    corpora    quadrige- 
mina,  51 
of  the  superior  olivary  nu- 
cleus, 56 
of   the  vestibular   nerveg 

40-43 
of  the  worm  (vermis),  58 
Cochlear,   the  nerve  of  hear- 
ing, 12 
Cochlear  nerve,  elective  vul- 
nerability of,  246,  247 
Cochlear  nuclei,  fibres  from, 

56 
Cochlear  receptors,  246 
Cold  irrigations,  effect  of,  233 
of   the  external   auditory 
canal,  245 
Column,  meaning  of  term,  79 
Commissura  arcuata  anterior 

of  Hannover,  70 
Commissura  habenulae,  65 
Constrictor    tonus,    inhibition 

of,  259 
Control  test  meals,  235 
Coordination,  disturbances  of, 
following   aural    irriga- 
tions, 244,  248 
Corona  radiata,  29,  31 

stimulation  of,  112,  316 
Coronal    plane,    rotations    in 
thcj  194,  203 


INDEX 


541 


Corpora  quadrigemina,  fibres 

to,  46,  50 
irritation  of,  167 
Corpus  callosum,  69 
fibre  paths  of,  75 
section  of  the,  112 
Corpus  striatum,   connections 

of  the,  73-78 
g-rey  matter  of,  73 
Corpus    subthalamicum,    con- 
nections of  the,  67 
grey  matter  of,  67 
Corpus  trapezoides,  formation 

of,  14 
Cortex  cerebri,  28 
Corti,  organ  of,  13 
Cortical   centres,    obstruction 

of  circulation  in  and  ver- 
tigo, 39 
Cortical  paths,  decussation  of, 

27 
Cortico-bulbar  tracts,  76 
Cortico-geniculate  tracts,  76 
Cortico-pontine  tracts,  76 
Corti co-rubral  tract,  fibres  of, 

76 
Cortico-spinal  tracts,  position 

of,  76,  77 
Cranial    motor    nuclei,    fibres 

from  cerebral  cortex  to, 

29 
Cranial  nerves,  22 

liable    to    pressure    from 

exudations,  28 
situation  of,  22 
Cranial    nuclei,    blood-supply 

of  the,  37-39 
Crista  acustica,  8,  10 
Crista  vestibuli,  openings  in,  3 
Cms  cerebri,  31 
Crustal  fillet,  29,  31,  50 
Cuneo-calcarine  cortex,  lesions 

of,  78 
Cuneus  and  calcarine  fissure, 

78 

Darkschweitsch,  nucleus  of,  24 
Deafness,  senile,  cause  of,  37 
Deiters'  nucleus,  42 

fibres  from,  55 

neurones  of,  19 

tract  from,  87 


Dentate  nucleus,  fibres  from, 
58 

Depressor  fibres  in  man,  102 

Descending  tracts,  ascending 
paths  of,  89 

Descending  vestibular  root, 
termination  of,  43 

Diagonal  plane,  effects  of  ro- 
tations in  the,  196,  205 

Diencephalon,  main  divisions 
of,  62 

Digestive  apparatus,  effects  of 
aural    irrigations    upon 
the,  233-249 
effects   of    rotation   upon 
the,  164-182 

Digestive  functions,  gastric, 
importance  of,  167 

Digitalon,  the  effect  of,  in  ro- 
tation, 137 

Dilator  contractile  tissues,  ex- 
citability of,  110 

Dilator  mechanism,  tonus  of, 
259 

Direct  sensory  cerebellar  tract 
of  Edinger,  confusion 
created  by  term,  42 

Disorientation  by  lapse  of 
vision,  297 

Distant  vision,  fixation  for, 
252 

Disturbances  in  equilibrium, 
subjective  interpreta- 
tion of,  241 

Dog,  ocular  movements  in  the, 
319 

Dogs,    Ferrier's   experiments 
on,  292,  293 
stimulation  of  cerebellum 
of,  291 

Dorsal  accessory  olivary  nu- 
cleus, 33 

Dorsal  decubitus,  method  of, 
in  counteracting  nausea 
in  rotation  sickness,  190 

Dorsal  fasciculi,    constituents 
of,  79 
pathways  of,  82 

Dorsal-spinal-ganglion  cells, 
emigration  of,  22 

Dorsal  spinal  root  ganglia,  in- 
flammation of,  31,  35 


542 


INDEX 


Dorsal  spino-cerebellar  fascic- 
ulus, 43 
pathway  of,  81,  82 

Dorsal  spino-cerebellar  tract, 
origin  of,  81,  82 

Drugs,  effect  of,  upon  the 
circulation  in  rotation 
sickness,  190 
the  influence  of,  upon  the 
circulatory  changes  that 
occur  with  rotations, 
134-139 

Ductus  endolymphaticus,  4,  6, 
7 

Dyspepsias,     nervous,    origin 
of,  167 


Ear,  diagram  of  the  perilym- 
phatic     and     endolym- 
phatic spaces  of  the  in- 
ner, 8 
internal,  measurement  of 

the,  3 
outer  wall  of,  3 
vestibule  of,  3 

Early  metencephalon,  dorsal 
zones  of,  48 

Edinger-Westphal  nucleus,  23 

Effector  neurone,  common 
path  of,  119 

Efferent  cerebellar  impulses, 
distribution  of,  299 

Efferent  cerebellar  path, 
through  inferior  olives, 
55 

Efferent  cerebellar  paths,  ocu- 
lar, 27 

E  ff  e  r  e  n  t  cerebellar  tracts 
through  undefined  paths, 
96 

E  ff  e  r  e  n  t  cerebello-pontine 
fibres,  end  of,  60 

Efferent  cerebello-pontine 
tract  in  the  middle  pe- 
duncle, fibres  of,  60 

Efferent  fibres  from  the  optic 
thalamus,  64 

Efferent  paths,  45,  47,  51,  53, 
54,  55,  56,  60,  61,  63,  67, 
68,  72,  74 

Eighth  nerve,  fibres  of,  13 


Electrotonus,   phenomena  of, 

279 
Eleventh  nerve,  bulbar  or  ac- 
cessory portion  of,  34 
Emboliformis,  part  of  nucleus 

dentatus,  58 
Embryological  studies  of  Kol- 

liker,  40 
Eminentia  arcuata,  4 
Eminentia  teres,  27 
End-brain,  constituents  of,  69 
Endolymph,    current  of,  266, 
284,  286 
flow  of,  267,  274 
forcing  the,  266,  278 
the,  6 
Epicritic     fibres,    description 

of,  94 
Equilibration,  active,  219 
adjustments  of,  312 
disorders  of,  181 
effects  of  aural  irrigation 

upon,  237-249 
reflex  acts  of,  313 
Equilibrium,  disorders  of,  243 
disturbances  of,  117,  127, 

130,  270 
disturbances   of,   compen- 
sated by  hypnotic  sug- 
gestion, 218 
effect    of    rotation   upon, 

192-197 
maintenance  of,  298 
subjective    interpretation 
of  disturbances  in,  241 
Erysipelas,  a  cause  of  nystag- 
mus, 333 
Ewald  test  meal,  description 

of,  164 
Extensor   muscles,    tonus   of, 

308 
External  auditory  canal,  irri- 
gations of,  20 
nystagmic   movements  in 
irrigation  of,  20 
External    geniculate    body, 

fibres  from  the,  70 
External  rectus  muscle,  27 
Eye,  flexible  mobility  of,  302 
long    ciliary    nerves     of, 

108 
movements  of  the,  20 


INDEX 


548 


Eye  area,  removal  of  part  of 

the  frontal,  326 
Eye  movements,   mechanisms 

controlling     horizontal, 

299 
in  response  to  vestibular 

stimulation,  41 
Eye  muscles,  fibres  for  move- 
ments of,  76 
nuclei  of  the,  15 
Eyeball,  antero-posterior  axis 

of  the,  and  rotary  nys- 

tag-mus,  199 
centre  of  rotation  of,  203 
muscular  apparatus  of,  203 
Eyeballs,   movements  of  the, 

320 
protrusion  of,  292 
Eyes,  adjustments  of  the,  327 
conjugate    movements   of 

the,  48 
conjugate     deviation     of, 

288,  317 
direct  movements  of,  316 
effects    of   rotation    upon 

the,  198-206 
exclusion    of    the    lateral 

movements  of,  240 
fibres  from  the,  95 
jumping  of  the,  216 
lateral  movements  of,  315 
limited  rotation  of,  315 
movements  of  the,  20 
movements  of,  in  response 

to  loud  sound,  15 
nystagmic  movements   of 

the,  205 
rotation  of,  271 
study  of  deviation  of,  286 
turning  of  the,  313 
voluntary  control  of  rotary 

movements  of,  240 


Facial  muscle?,  motor  inner- 
vation of,  31 
Facial  nerve,  motor  and  sen- 
sory root  of,  12 
nucleus  of,  25 
Fasciculus,  definition  of  a,  79 
Fasciculus  retroflexus  of  Mey- 
nert,  origin  of,  65 


Fasciculus  solitarius,  fibres  of, 

32,  33 
Fasciculus     sulco-marginalis, 

51 
Fastigio-bulbar  fibres,  58 
Ferrier's  experiments  on  cere- 

bello-pontine  fibres,  45 
Fibre  paths,   in   red   nucleus, 

311 
Fibres  of  the  cerebellum,  45- 
49 
of  the  corpus  striatum,  73 
of  the  corpus  subthalami- 

cum,  67 
of  the  inferior  colliculi,  53 
of  the  inferior  olivary  nu- 
cleus, 54 
of  the  lateral  fillet,  52 
of  the  lateral   geniculate 

body,  52 
of  the  mammillary  nucle- 
us, 68 
of  the  median  geniculate 

bodies,  54 
of  the  mesial  fillet,  49 
of  the  optic  thalamus,  62 
of  the  pontine  nucleus,  59 
of  the  red  nucleus,  60 
of  the  rhinencephalon,  72 
of  the   substantia   nigra, 

67 
of  the  superior  colliculi,  51 
of  the  superior  olivary  nu- 
cleus, 56 
of  the  vestibular  nerves, 

40-43 
of  the  worm,  58 
Fifth  nerve,  a   mixed  nerve, 
28 
chief  motor  nucleus  of,  28 
connections  of  motor  part 

of,  29 
connections  of  sensory 

part  of,  28 
fibres  of,  28 
motor  fibres  of,  29 
sensory  nucleus  of,  28 
Fila  anastomica,  12 
Fishes,    vestibular    nerve   of, 
20,  71 
optic  fibres  of,  21 
Flechsig,  tract  of,  43 


544 


INDEX 


Flocculus,  irritation  of  the, 
292,  301 

Food,  active  absorption  of,  234 
improperly  digested,  167 

Foramen  of  Magendie,  situa- 
tion of,  59 

Foramina  nervosa,  13 

Foramina  of  Luschka,  59 

Forel,  decussation  of,  61 
field  of,  67 

Formatio  reticularis,  periph- 
ery of  lateral  field  of,  41 

Formatio    reticularis    grisea, 
cells  of,  44 
traversed  by  sensory  root, 
32 

Fossa  sulciformis,  position  of 
the,  3 

Fourth  nucleus,  position  of, 
26 

Fovea  vagi,  32 

Frenulum  veli,  27 

Frog,  decerebrate,  jumping  of, 
54 

Frogs,  section  of  the  horizon- 
tal canals  of,  126,  127 

Frontalis  muscles,  31 

Fronto-cerebellar  tract,  con- 
stituents of,  59 

Fundic  musculature,  contrac- 
tion of,  180 

Fundus  oculi,  changes  that  oc- 
cur in  the,  during  rota- 
tions, 206 

Galvanic  current,  effects  of, 
upon  the  semicircular 
canals,  268-272,  279 

Galvanic  stimulation  of  the 
cervical  sympathetic, 
109 

Galvanism,  mechanism  of,  288 

Galvanization  of  the  sympa- 
thetic in  the  neck,  261 

Ganglion  trunci  vagi,  homo- 
logues  of,  36 

Ganglionectomy,  general  ef- 
fect of,  109 

Gasserian   ganglion,    contents 
of,  28 
inflammations  of,  30 
removal  of,  30 


Gastric  congestion  in  aural 
irrigations,  177 

Gastric  crises  of  tabetic  ori- 
gin, irrigations  of  little 
effect  in,  246 

Gastric  disturbances,  origin 
of,  182 

Gastric    glands,    secretory 
fibres  for,  101 

Gastric  juice,  secretion  of  nor- 
mal, 172 

Gastric  motility,  testing,  234 

Gastric     mucous     membrane, 
congestion  of,  181 
secretion    of    fluid    by, 
175 

Gastrin,  171 

Geniculate    ganglion,    inflam- 
mation of,  30 
situation  of,  29 

Gennari,  the  white  line  of, 
78 

Glasserian  fissure,  30 

Globosus,  part  of  nucleus  den- 
tatus,  58 

Globus  pallidus,  67 

Glosso-pharyngeal  nerve, 
stimulation  of  the,  166 

Golgi  method,  use  of,  79 

Golgi-Mazzini  organs,  struc- 
ture of,  85 

Goll,  fasciculus  of,  82 

Gowers'  tract,  description  of, 
83 
fibres  from,  46 

Grey  matter,  cells  of,  86 

Grey  matter  of  the  cerebel- 
lum, 57,  58 

Grey  rami,  100 

Grey  root  of  the  optic  nerves, 
69 

Gudden,  fibres  of  inferior  com- 
missure of,  54 

Gyrus  fornicatus,  anterior  por- 
tion of,  78 

Habenulo-peduncular  tract,  fi- 
bres of,  65 

Hair  cells,  cylindrical,  descrip- 
tion of,  10 

Head,  deviations  of,  in  rota- 
tions, 277,  278 


INDEX 


545 


Head,  fibres  for  glands,  blood- 
vessels, and  plain  muscle 
of  the,  100 
ganglia  of,  98 
turning  of  the,  313 

Head  movement,  centres  for, 
313 

Heart,  accelerator  fibres  for, 
102 

Helweg,  fasciculus  of,  82,  83 
fibres  from,  55 

Helweg's    bundle,   connection 
of,  42 

Hemisphaerium,  the,  69 

Herpes  zoster,  origin  of,  31 
of  the  tympanum,  30 

Hippus,    the    study    of,    250, 
251 

Homolateral     pupillary     con- 
striction, 261 

Horizontal  canal,  openings  of 
the,  4 

Horizontal     nystagmus,     195, 
278,  295 
movements   of,    195,    199, 
200,  242,  300,  301 

Hot    irrigations,    effects    of, 
upon  the  left  ear,  237 

Human    cerebellum,    develop- 
ment of,  48 

Hydrochloric  acid,   effect   of, 
upon  gastric  stasis,  174 

Hyoscyamin,  effect  of,  in  rota- 
tion, 137,  138 
use   of,    in   counteracting 
effects  of  rotation  sick- 
ness, 191 

Hypnosis,  before,  during,  and 
after    irrigations,    212- 
218 
waking,  184,  213 

Hypnotic   state,    after-effects 
of,  185 

Hypnotic  suggestion,  as  a 
means  of  counteracting 
irrigation  sickness,  219 
disturbances  of  equilibri- 
um following  irrigations 
compensated  by,  218 
notes  taken  of  the  effect 
of,  in  aural  irrigations, 
183,  212 


Hypnotism  as  a  curative  agent 

in  all  sorts  of  conditions, 

183 
Hypoglossal    nerve    (the 

twelfth),  a  pure  motor 

nerve,  35 

Impulses,  inhibitory,  paths  of, 
in  cord,  92 
from  semicircular  canals, 

92 
in  spinal  cord,  paths  of,  92 
mutual  reinforcement  of, 

177 
reflex,  paths  of,  in  cord,  92 
sensory  paths  of,  in  cord,  92 
Inferior    cerebellar     commis- 
sure, bundles  of,  58 
Inferior  colliculi,  connections 
of  the,  53 
efferent  fibres  of,  53 
Inferior    colliculus,     cochlear 
paths  to  the,  56 
neurones  of  the,  16 
Inferior    frontal   convolution, 

cortex  of,  26 
Inferior    medullary    velum, 

white  matter  of,  59 
Inferior  olivary  nucleus,  con- 
nections of  the,  54-56 
Inferior  olive,  fibres  from,  55 
lesions  of,  42 
relation  of,  44 
Inferior     peduncle,     efferent 
cerebellar  tracts  by  way 
of  the,  96 
paths  through  the,  94,  95 
section  of,  314 
study  of,  314 
Inhibition,  intimate  nature  of, 
122  ^ 

period  of,  300 
seat  of,  122 
state  of,  294,  295 
Inhibitory  impulses,  92 
Internal  auditory  artery,  37 
Internal    auditory  vein,  blood 

returned  by,  37 
Internal  cerebellar  nuclei,  57 
Internal  rectus,  inhibition  of, 

110 
Interpeduncular  ganglion,   66 


546 


INDEX 


Intersegmental  tracts,  mean- 
ing of,  90 
Intestine,  rhythmic  segmenta- 
tion of,  168 
Intestines,  rhythmic  contrac- 
tions of,  166 
Invertebrates,     sensory    cells 

of,  22 
Irrigating  fluid,   temperature 

of,  242,  243,  248 
Irrigation,  balancing  tests  be- 
fore, 213 
equivalents  of,  247-249 
onset  of,  240 
Irrigation  tests,  270 
Irrigations,  aural,  the  general 
effects  of,  207-219 
cold,  effect  of,  233 
cold  unilateral,  235 
cold  bilateral,  235 
experiments  with  cool,  243 
general  study  of,  251 
immediate  effect    of    hot 

and  cold,  254 
of  the  left  ear,  239 
walking  after,  244 

Jugular  foramen,  and  gan- 
glion of  vagus,  33 

Jugular  vein,  blood  and  lymph 
passing  into  from  laby- 
rinth, 38 

Katelectrotonus,  state  of,  280 
K  I  test  for  absorption,  186- 

189,  236 
Knee-jerks,     deviations      of, 

from  the  normal,  245 

Labium  tympanicum,  13 
Labyrinth,  anatomy  of,  3-11 
blood-supply  of  the,  37-39 
bony,  diagram  of,  5 
bony,  division  of,  3,  5 
vessels  of,  38 
Labyrinthine  artery,   part  of 

brain  system,  37 
Labyrinthine  balanced   mech- 
anisms, 294 
Labyrinthine  impressions,  as- 
sociated with  cerebellar 
function,  179 


Labyrinthine  impressions,  cor- 
roboration of,  277 

Labyrinthine  nystagmus,  296 

Labyrinthine  paths,  71 

Labyrinthine  phenomena, 
mechanism  of,  274 

Labyrinthine  receptors,  effect 
of  cold  upon,  181 
effect   of   hot    irrigations 

on,  272 
effect  of  rotations,   aural 
irrigations,  and  galvan- 
ism on,  273-287 
effects  of  thermic  irrita- 
tion of,  219 
irritation  of  the,  172,  248 
irritation    and     irregular 
stimulation  of,  181 

Labyrinthine  tonus  mechan- 
isms, existence  of  bila- 
teral, 125 

Lagena  of  lower  animals,  11 

Lamina  cinerea,  description 
of,  69 

Lamina  spiralis  ossea,  position 
of,  4 

Laminae,  secondary  and  ter- 
tiary of  cerebellum,  57 

Langley,  post-ganglionic  fibres 
of,  90 

Larynx,  extrinsic  muscles  of, 
35 

Lateral  cochlear  nucleus,  14 

Lateral  fillet,  connections  of 
the,  52,  53 
fibres  from  nucleus  of,  53 

Lateral  geniculate  body,  con- 
nections of  the,  52 
grey  nuclei  of,  62 

Lateral  horn  cells,  analogue 
of,  44 

Lateral  occipital  lobe,  lesions 
of,  78 

Lateral  root,  fibres  of,  in  man, 
70 

Lateral  ventricle,  inferior  horn 
of,  75 

Lateral  vestibular  nucleus,  18 

Legs,  sleepy  feeling  in,  244 

Lemniscus,  connections  of  the, 
49,  50 

Lemniscus  lateralis,  52,  53 


INDEX 


547 


Lenticular  nuclei,  fibres  of,  63 

Levatores  palpebrarum,  inner- 
vation of,  31 

Ligamenti  labyrinthi  canalicu- 
lorum,  7 

Lingula,  rudimentary  folia  of, 
59 

Lissauer,  constituents  of  zone 
of,  80 

Locomotion,  reflex -mechanism 
of,  91 

Locomotor  ataxia,  effect  of  ir- 
rigations in,  246 

Lump-sensation  in  the  stom- 
ach, 268 

Lump-sensations  during  rota- 
tions, 170 

Luschka,  foramina  of,  59 

Luys,  position  of  nucleus  of, 
67 

Maculae  acusticae,  measure- 
ments of,  9 

Maculas  of  the  utricle,  hairs 
of,  11 

Magendie,  foramen  of,  situa- 
tion of,  59 

Mammifera,  otoliths  in,  128 

Mammillary  nucleus,   connec- 
tions of  the,  68-72 
fibres  to  the,  68 

Mammillo-tegmental  tract,  fi- 
bres of,  69 

Mammillo-thalamic  tract,  68 
fibres  in,  63 

Massa  intermedia,  constitu- 
ents of,  62 

Mechanisms,  balanced,  329 

Median  geniculate  bodies,  fi- 
bres from,  54 

Median  geniculate  bodies,  con- 
nections of  the,  54 

Median  geniculate  body,  neu- 
rones of  the,  16 

Median  sagittal  bundle  of  su- 
perior medullary  velum, 
59 

Median  vestibular  nucleus,  18 

Medulla,  blood-supply  by  ver- 
tebral arteries,  38 

Medulla  oblongata,  27 
blood-supply  of,  38 


Medullary  circulation,  nature's 
defence  against  failing, 
132 

Medullary  fibres,  degeneration 
of,  107 

Medullary  lamina,  fibres  of,  62 

Meissner's  corpuscles,  devel- 
opment of,  84 

Meissner's  plexuses,  cells  and 
fibres  of,  165 

Meissner  and  Auerbach,  plex- 
uses of,  98 

Membranous  canals,  experi- 
ments of  Ewald  and 
Breuer  on,  273 

Membranous  labyrinth,  posi- 
tion of,  6 

Memory,  loss  of,  78 

of  printed  words,   centre 
for,  78 

Mesencephalic  centres  in 
fishes,  20 

Mesencephalic  root,  descend- 
ing, 29 

Mesencephalon,  in  fishes,  178 
in  lower  animals,  71 

Mesenteric  nerves,  stimulation 
of,  173 

Mesial   fillet,    connections    of 
the,  49,  50 

Meynert,  commissure  of,  50 
fasciculus   retroflexus  of, 
origin  of,  65 

Middle  cerebellar  peduncle, 
contents  of,  46 

Middle  peduncle,  efferent  cere- 
bellar tracts  through 
the,  96 
paths  through  the,  95 

Migraine  and  the  cerebellar 
mechanisms,  336 

Modiolus,  central  canal  of  the, 
13 

Monakow's  tract,  fibres  of,  86 

Monkey,  pupil  constriction  in 
the,  from  the  angular 
gyrus,  113 
stimulation  of  various 
parts  of  cerebellum  of 
the,  290 

Monkeys,  division  of  the  in- 
ternal rectus  of,  31^ 


548 


INDEX 


Morphin,  effects  of,   in  rota- 
tions, 136 
nausea  caused  by,  178 

Motility,  tests  for,  189 

Motor  nerves,  influence  of 
auditory  impulses  on,  15 

Motor  neurones,  influence  of 
psychic  impressions 
over,  179 

Motor  writing  centre,  exist- 
ence of,  78 

Mucous  membrane,  decoctions 
and  extracts  of  the  py- 
loric, 171 
effect  of  extracts  made 
from  various  portions 
of,  186 

Mucus,  excessive  amounts  of, 
176 

Muscle  spindles,  fibres  of,  85 

Muscles  of  the  body,  tonus  of, 
93 

Muscles  of  the  face,  motor  in- 
nervation of,  31 

Muscles  of  the  pharynx,  motor 
fibres  of,  32 

Muscular  apparatus  of  the 
eyeball,  203 

Muscular  contractions,  jerky 
irregularities  in,  247 

Myelin  sheath,  first  appear- 
ance of,  72 

Nausea  and  vomiting,  mech- 
anism of,  132 
phenomena  of,  177,  182 

Nausea,   caused   by  morphin, 
178 
origin  of  feeling  of,  178 

Near  vision,  fixation  for,  252, 
255 

Nerve  centres,  rhythmic  ac- 
tivity of,  257 

Nerve  deafness,  246 

aural  irrigations  a  possible 
aid  in  the  treatment  of, 
249 

Nerve  degeneration,  danger 
of,  247 

Nerve  elements,  degeneration 
of,  110 

Nerve  fibres,  origin  of,  13 


Nerve  roots,  T-bifurcation  of 
the  posterior,  80 

Nerve,  the  eighth,  description 
of,  12 

Nervous  dyspepsias,  origin  of, 
167 

Nervous  system,  intimate 
functional  relations  of 
the  various  parts  of,  122 

Nervus  erigens,  sympathetic 
fibres  of,  102 

Neuro-epithelial  cells,  13 

Neuro-epithelium,  intimate  re- 
lation of  nerve  filaments 
to,  17 

Neuro-vascular  mechanisms, 
exhaustion  of  the,  136 

Ninth  nerve,  motor  portion  of, 
32 
root  fibres  of,  33 

Nitroglycerin,  effect  of,  in  ro- 
tations, 135 

Nociceptive  reflexes,  121 

Nociceptors,  definition  of,  120 

Nose  and  mouth,  nerves  for 
glands  and  blood-vessels 
of  mucous  membrane  of, 
101 

Nucleo-cerebellar  tract,  con- 
stituents of,  19 

Nucleus    ambiguus,    fibres 
from,  35 
position  of,  32 

Nucleus  cuneatus,  fibres  from, 
49 

Nucleus  dentatus,  fibres  of,  43 
atrophy  of,  43 

Nucleus  fastigii,  axones  of,  58 
end  of,  44 

Nucleus  gracilis,  fibres  from, 
49 

Nucleus  lateralis,  cells  of,  44 

Nucleus  lemnisci  lateralis,  15 

Nucleus  masticatorius,  28 

Nucleus  olivarius  superior,  14 

Nucleus  pontis,  fibres  from,  57 

Nucleus  ruber,  connections  of 
the,  60-62 

Nucleus     Tegmenti,     connec- 
tions of  the,  60-62 

Nucleus  trapezoideus,  cells  of, 
56  ' 


INDEX 


549 


Nucleus  trapezoideus,  constit- 
uents of,  14 
Nucleus  ventralis,  position  of, 

32 
Nystagmus,   apparent    move- 
ment of  objects  in  hori- 
zontal, 200 

cause  of,  in  aural  irriga- 
tions, 243,  295 

cerebellar  differentiated 
from  labyrinthine,  334 

due  to  rotation,  197 

from  erysipelas  over  mas 
toid  area,  333 

general  effect  of  a  mixed 
horizontal  and  rotary, 
263 

horizontal,  195,  278,  295 

in  animals,  329 

in  rotations,  coordinated 
movements  of,  304 

labyrinthine,  296 

latent  vertical,  239 

miner's,  332 

mixed,  271,  274 

momentary,  38,  39 

nervous  mechanism  of,  289 

occurrence  of,  331-335 

ocular,  296 

of  rotations,  mechanism 
of,  288-290 

physiological,  329 

rotary  element  of,  195,  200 

secondary,  203 

simultaneous  presence  of 
three  forms  of,  240 

spontaneous,  320,  327,  329 

teething,  333 

twofold,  197 

use  of  term  explained,  198 

vertical,  204,  244,  266,  267, 
276,  282,  300,  321 

violent,  215 

visible,  332 

Oblique,  paresis  of  right  supe- 
rior and  left  inferior, 
306 

Occipital  cortex,  70 
fibres  of,  52,  63 

Ocular  area,  stimulation  of  the 
frontal,  303 


Ocular  centre,  blood-supply  of, 
39 

Ocular  and  cerebellar  centres, 
blood-supply  of,  38 

Ocular  movements  and  nystag- 
mus, 315-330 

Ocular  movements,  association 
of,  113 
location  of  centres  for  re- 
flex, 260 

Ocular    muscles,   associations 
of,  285 
innervation  of,  39 
summary  of  the  relations 
of,  284-287 

Ocular  nystagmus,  296 

Oculo-motor  centres,  20 

Oculo-motor  fibres,  origin  of, 
24 
decussation  of,  24 

Oculo-motor  nuclei,  relations 
of  the  semicircular  ca- 
nals to  the,  306 

Olfactory  cortex,  projection 
fibres  of,  71 

Olfactory  lobe,  fibres  of,  75 

Olfactory  nerve,  central  rela- 
tions of,  22 
primary  afferent  neurones 
of,  83 

Olfactory  organs,  recession  of, 
179 

Olivary  cells,  axones  of,  55 

Olivary  fasciculus,  connection 
of,  42 

Olive,  experimental  phenom- 
ena of,  44 

Olivo-cerebellar  fibres,  43 

Optic  and  sensory  spinal  ele- 
ments, analogy  between, 
22 

Optic  atrophy,  296 

Optic  chiasm,  location  of,  69 
paths  of,  69 

Optic  nerve,  components  of, 
22 

Optic  nerves,  grey  root  of,  69 

Optic  pathways,  71 

Optic    thalamus,    connections 
of  the,  62-65 
fibres  from  cells  of,  50 
fibres  to  the,  61 


550 


INDEX 


Optic  tract,  paths  in  the,  70 
Optics,  principles  of,  202,  203 
Orbicularis  palpebrarum,  31 
Organism,    defences    of    the, 
against  noxious  sub- 
stances, 167 
Organs  of  special  sense,  fibres 

from,  96 
Otoconium,  composition  of,  11 
Otolithic   apparatus,    inactive 

state  of,  134 
Otolithic  membrane,  descrip- 
tion of,  10 
Otoliths,  composition  of,  10 
in  mammifera,  128 
of  fishes,  11 

Pain,  sensation  of,  paths  for, 
83 

Pancreatic  glands,  secretory 
fibres  for,  101 

Paradoxical  pupil  contraction, 
phenomenon  of,  107 

Paradoxical  pupil  dilatation, 
modus  operandi  of,  258 

Paraesthesiae,  occurrence  of, 
245,  335 

Pars  intermedia,  12 

Passive   rotation,    effects   of, 
130-139 
disturbances  in,  130 
position  of  the  body  dur- 
ing,  130 

Peduncle,  inferior  cerebellar, 
14 

Pedunculus  corporis  mammil- 
laris,  fibres  of,  69 

Peripheral  neurones,  location 
of  afferent,  83 

Peripheral  terminals  of  effer- 
ent paths,  94 

Peripheral  terminations  of  af- 
ferent paths,  83-94 

Peristalsis,    after   vagus   sec- 
tion, etc.,  168 
first  signs  of,  after  vagus 
section,  etc.,  169 

Peripheral  stump  of  vagus  and 
splanchnic  nerves,  stim- 
ulation of,  165 

Pharynx,  innervation  of 
ITiuscles  of  the,  32 


Pigeons,  experiments  on   the 
semicircular   canals  of, 
125,  126,  127 
Ferrier's  experiments  on, 

293 
pupil  constriction  in,  113 

Pig's  stomach,  cardiac  and  py- 
loric sphincters  of,  166 

Pilocarpin,  in  inflammatory 
conditions  affecting  the 
internal  ear,  212 

Planum  semilunatum,  9,  10 

Pons,  supplied  by  vertebral 
arteries,  38 

Pontine   nucleus,   connections 
of  the,  59,  60 
fibres  from  cells  of,  45 

Posterior   commissure,    paths 
of,  66 
constituents  of,  66 
position  of,  58 

Posterior  canal,  ampullary  end 
of,  4 

Posterior  longitudinal  fascicu- 
lus, connections  of,  51 
crossed  and  uncrossed  fi- 
bres to  the,  41 
fibres  of,  26,  66,  69 
relation  of,  to  nerves,  41 

Posterior  median  fasciculus, 
41 

Posterior  median  sulcus,  area 
of,  79 

Posterior  nerve-root,  collater- 
als and  terminals  of,  80, 
81 

Posterior  nerve-roots,  T-bifur- 
cation  of,  80 

Posture,  tonic  reflexes  of, 
122 

Potassium,  the  effect  of  bro- 
mid  of,  in  rotation,  136 

Praecentral  gyrus,  32 

Preganglionic  fibres,  100 
course  of,  100 
of    the   sympathetic   ner- 
vous system,  90,  99 

Prepotent  reflexes,  121 

Primary  sensory  neurones, 
cells  of,  32 

Proprio-spinal  neurone,  con- 
nections of,  119 


INDEX 


551 


Protocols  of  experiments  on 
rotation  subjects,  139- 
163 

Protocols  on-  irrigation  sub- 
jects, 220-232 

Pseudo-affective  reflex,  121 

Psychical  secretion,  gastric, 
171 

Pulse-rate,  changes  in,  during 
irrigations,  253 

Pulvinar,  fibres  from  the,  70 

Pupil  constriction,  centre  for, 
107 
in  the  monkey  and  in  pig- 
eons, 113 

Pupil  dilatation  and  constric- 
tion, effects  of.  111, 
113 

Pupil,  rhythmic  dilatations  of 
the,  259 

Pupillary  constriction,   homo- 
lateral, 109 
mechanism  of,  105,  106 

Pupillary  dilatation,  mechan- 
isms of,  251,  252 

Pupillary  fibres,  views  on  the 
paths  of  the,  106 

Pupillary  movements,  the 
paths  involved  in,  105- 
113 

Pupillary  phenomena  in  hot  ir- 
rigations, 250 

Pupillary  reactions,  study  of, 
251 

Pupillo-constrictor  mechan- 
ism, hypertonus  of,  258 

Pupillo-constrictor  path,  107 

Pupillo-dilator  muscle,  exist- 
ence of,  108 

Pupillo-dilator  tract,  position 
of,  108 

Pupils,  condition  of,  following 
cold  irrigations,  250 
inequality  of,  260 
irregularity  of,  107 
state    of,    in    irrigations, 
259 

Purkinje  cells,  axones  of,  45 
fibres  from,  45 

Putamen,  fibres  from  the,  67 

Pyloric  circular  fibres,  inhibi- 
tion of  the,  166 


Pyloric   closure   during    rota- 
tions,   maintenance    of, 
170 
Pylorus,    closure  of,  in  rota- 
tions, 165 

delicate  local  mechanisms 
of,  170 

explanation  of  mechanism 
of  opening  of  the,  166 

stenosis  of  the,  and  the 
labyrintho-cere  b  e  1 1  a  r 
mechanisms,  336 

tightly  closed  in  aural  ir- 
rigations, 235 
Pyramidal  tract,  lesion  of  di- 
rect, 86 

Quadriceps  extensor,  inhibi- 
tion of  the,  296 

Quadrigemina,  inferior  collic- 
ulus  of  the,  16 

Rabbits,  Ferrier's  experiments 
on,  292 
section  of  the  semicircular 

canals  in,  126 
stimulation  of  cerebellum 
of,  290 

Radial  pulselessness  in  rota- 
tions, 131 

Radix  cochlearis,  12 

Radix  vestibularis,  12 

Receptor  organs,  division  of, 
120 

Recessus  ellipticus,  grooves 
of,  3,  6 

Recessus  utriculi,  blind  sac 
of,  6 

Reciprocal    innervation,    294, 
297 
phenomenon  of,  122 
theory  of,  258 

Rectus,  paresis  of  the  left  ex- 
ternal, 306 

Recumbency,  supine,  potency 
of,  in  relaxing  the  py- 
lorus, 186 

Red  nucleus,  connections  of 
the,  60-62 

Red  nucleus  cells  in  animalg 
and  man,  65 


552 


INDEX 


Red  nucleus  neurones,  axones 

of.  47 
Reflex  balanced  mechanisms, 

disturbance  of,  273 
Reflex  complication,  121 
Reflex  impulses,  92 
Reflex  paths,  protective,  70 
Reflexes,  prepotent,  121 
compounding  of,  121 
pseudo-affective,  121 
Refraction,  changes  in,  256 

errors  of,  257 
Regurgitations  in  animals,  180 
Retardation,    reaction   of,  267 
Retina,  movement  of   images 

upon,  262,  267 
Retinal  anaemia,  109 
Retinal  impressions  of  passing 

objects,  71 
Retinal  pigmented  epithelium, 

109 
Retinal  vessels,  hyperaemia  of, 

261 
Rhinencephalon,     connections 
of  the,  72,  73 
constituents  of,  71 
Rolando,  cells  in  the  substance 
of,  80,  81 
fissure  of,  75 
Roof   nuclei,   decussation   of, 

59 
Rotary   nystagmus,   267,   282, 
283,  301.  322 
apparent  movement  of  ob- 
jects in.  201,  202 
mechanism  of,  285 
production  of,  195 
study  of,  203 

vision   impossible  during, 
262 
Rotation,  brisk,  in   the  coro- 
nal plane,  195 
Rotation,  coronal  element  in, 
199 
disturbances  in.  130 
effect  of  acceleration  upon 

subjects,  193 
effect  of  glycerin  in.  135 
effect  of   mild,  upon   the 

circulation,  131 
effect  of,   upon  equilibri- 
um, 192-197 


Rotation,  effects  of,  upon  the 
digestive  apparatus, 
164-182 

effects  of,  upon  the  eyes, 
198-206 

effects  of  passive,  130-139 

increased  blood-pressure 
in,  132 

in  perverting  gastric  func- 
tion, efficiency  of,  234 

in  the  sagittal  plane, 
279 

nystagmus  due  to,  197 

position  of  the  body  dur- 
ing, 130 

protocols  of  experiments 
of,    upon    various    sub- 
jects, 139-163 
Rotation  sickness,  eructations 
in,  180 

hypnotic  suggestion  in  off- 
setting effects  of,  190 

prevention  of,  183 

train  of  symptoms  set  up 
in,  138 

vascular     congestion     of 
stomach  accompanying, 
170 
Rotation    subjects,    effect    of 
swings  upon,  192 

experiments  on.  184-191 
Rotation  test  meals,  164 
Rotations,  closure  of  pylorus 
in,  165 

diminished  secretion  of 
gastric  juice  in,  172 

displacement  of  the  head 
in.  193 

effect  of.  in  the  coronal 
plane.  194.  203 

effect  of.  in  the  mesial 
plane,  194 

effect  of  repeated,  upon 
the  pulse.  132 

effects  of  strychnin  and 
morphin  in.  136 

in  recumbency,  134 

in  the  sagittal  and  coronal 
planes.  132 

in  the  sagittal  and  diago- 
nal planes,  effects  of, 
196 


INDEX 


55a 


Rotations,  in  the  upright  posi- 
tion, conclusions  on,  133 
increase  of  salivary  flow 

in,  189 
influence  of  drugs  upon  the 
circulatory  changes  that 
occur  with,  134-139 
rise  of  blood-pressure  af- 
ter, 132 
salivary  flow  in,  164 
Rotations  with  subject   lying 

horizontally,  164,  165 
Rotations  with  subject  sitting 

upright,  164 
Rubro-spinal    tract,     efferent 
impulses  of,  61 
fibres  of,  86 

Saccule,  hairs  of,  11 
structure  of,  9 

Sagittal  plane,  effects  of  rota- 
tions in  the,  196,  204 

Salivary  flow,  increase  of,  in 
rotations,  164,  189 

Salivary  glands,  secretory  and 
vaso-dilator  fibres  for, 
31 

Salol  test  for  stomach  motil- 
ity, 234 

Salol  tests  in  rotations,  164 

Schultze,  "comma' '  tract  of,  89 

Scratch  reflex,  end  effect  of 
positive  sign,  121 

Secondary  nystagmus,  203 

Secretin,  gastric,  171 

Secretin  in  the  pyloric  portion 
of  the  mucous  mem- 
brane, 172 

Secretogogues  in  food,  action 
of,  171 

Secretory  fibres  for  salivary 
glands,  31 

Semicircular  canal  apparatus, 
theories  concerning,  128 

Semicircular     canals,     blood- 
supply     from     internal 
auditory  artery,  37 
connections  of,  294 
description  of,  4 
effects    of    the    galvanic 
current  upon   the,   268- 
272,  279 


Semicircular  canals,  impulses 
from,  92 
intimate  relations  between 
and  the  function  of  equi- 
libration, 125 
literature  of,  125 
location   and  direction  of 

the,  266 
membranous,  7 
nausea  and  vomiting  fol- 
lowing disturbances  of, 
177 
not  in  direct  relation  with 
the  medullary  vaso-con- 
strictor  centres,  133 
of  pigeons,  125 
of  rabbits,  126 
of  frogs,  126 
openings  of,  6 
peripheral   end  organs  of 

the,  117 

physiology   of    the,    from 

the  standpoint  of  animal 

experimentation,  125-129 

receptors  of,  280 

relations  of  the,  to  the  oc- 

ulo-motor  nuclei,  306 
structure  of,  9 
study  of,  114,  125,  289 
Semilunar     lobule,    irritation 

of,  292 
Senile  deafness,  cause  of,  37 

hot  irrigations  in,  246 
Sense  of  seeing,  hearing,  and 

smelling,  78 
Sense   of  taste,   cells   related 

to,  32 
Sensory  cerebellar  tract,  42 
Sensory  cranial  nerves,  fibres 
from  reception  nuclei  of, 
49 
Sensory    fibres,    systems    of, 

93 
Sensory  impulses,  92 

question  of,  85 
Sensory  nerves  of  external  au- 
ditory canal,  effects  of 
thermic   stimulation  of, 
251 
Sensory   neurones,  peripheral 

endings  of,  84 
Sensory  pupil  reflex.  111 


554 


INDEX 


Septo-marginal  tract,  fibres 
of,  89 

Septum  transversum,  8 

Seventh  nerve,  afferent  fibres 
of,  30 
motor  nucleus  of  the,  31 

Sheep,  section  of  right  vestib- 
ular nerve  in,  319 

Shock,   Porter's  view  of   the 
mechanism  of,  134 
Crile's  view,  134 
Henderson's  view,  134 

Simple  reflex  arc,  composition 
of,  118 

Sinus  posterior,  connection  of, 
6 

Sinus  superior,  position  of,  7 

Sinus  utricularis,  wall  of  the, 
7 

Sixth  nerve,  fibres  to  nucleus 
of,  56 

Sixth  nucleus,  fibres  to  the,  40 
multipolar  cells  of,  27 

Skin,  temperature  of  the  hu- 
man, 207 

Skin-vessels,  constriction  of, 
275 

Smell,  centre  for,  78 

perversion  of  sense  of,  179 

Sound  vibrations,  the  tympa- 
num as  a  means  of  com- 
munication of,  246 

Spatium  perilymphaticum,  6 

Spinal  cord,  ascending  tracts 
of,  79 
fibres  to  the,  41 
impulses,  paths  of,  in,  92 
pathways  in  the,  79-83 

Spinal  dog,  a,  91 

Spinal  ganglia,  fibres  from,  84 

Spinal  ganglion,  cells  of  the, 
13 

Spinal  nerves,  root  cells  of 
the,  19 

Spinal  reflexes,  pathway  for, 
80 

Spinal  segment,  somatic  and 
splanchnic  roots  of,  35 

Spinal  vestibular  nucleus,  18 

Spino-spinal  neurones,  91 

Spino-spinal  paths,  existence 
of  reflex,  91 


Spino-tectal  and  spino-thala- 
mic  tracts,  cells  of,  81, 
82 

Spino-tectal  fibres,  51 

Spiral  canal,  dendritic  pro- 
cesses in  the,  13 

Splanchnic  nerve,  effect  of 
stimulation  of,  166 

Splanchnics,  bilateral  section 
of  the,  168 
section  of  the,  169 

Spontaneous  nystagmus,  320, 
327,  329 

Staloliths,  function  of,  11 

Stasis  of  the  stomach  contents 
in  rotations,  164 

Statocysts,  function  of,  11 

Stomach,  condition  of  the,  in 
the  hypnotic  state,  184 
effect  of  rotation  upon,  176 
loss  of  muscle  tonus  in, 

165 
lump-sensation  in,  180 
resistance   of   the,   to   all 
sorts  of  insult,  167 

Stomach  and  intestine,  gen- 
eral contractions  of,  166 

Stomach  cavity,  division  of, 
into  compartments,   173 

Stomach  functions,  effect  of 
aural  irrigations  upon 
the,  233 

Stomach  motility,  salol  test 
for,  234 

Stomach    movements,    inhibi- 
tion    of,    through     the 
splanchnics,  169 
initial  signs  of,  after  va- 
gus section,  etc.,  168 

Stomach  muscles,  augmentor 
fibres  for,  165 

Stomach  tube,  hemorrhage  at- 
tributed to,  177 

Stomachs,  experience  in  wash- 
ing out,  173 

Stooping,  sudden,  and  vertigo, 
38 

Stratum  zonale,  fibres  of,  63 

Striae  acusticae,  14,  27 

Striae  medullares,  fibres  of,  65 
probable    constituents    of 
the,  65-67 


INDEX 


555 


Strychnin  and  atropin,  influ- 
ence of,  in  rotations, 
134 

Subarachnoid  space,  communi- 
cation of,  with  fourth 
ventricle,  59 

Sublingual  ganglion,  named  by 
Langley,  31 

Sublingual  salivary  glands, 
secretory  and  vaso-dila- 
tor  fibres  of,  31 

Submaxillary  ganglion,  cells 
of  the,  31 

Submaxillary  glands,  secreto- 
ry and  vaso-dilator  fibres 
of,  31 

Subordinate  nystagmus,  197 

Substantia  ferruginea,  pig- 
mented cells  of,  29 

Substantia  gelatinosa,  28,  33 
fibres  from,  50 
neurones  within  the,  19 

Substantia  nigra,  fibres  from, 
51,  52 
location  of  upper  extrem- 
ity of,  67 
probable    connections     of 
the.  67 

Subthalamic  body,  grey  nuclei 
of,  62 

Subthalamic  region,  position 
of,  66 

*' Successive  degeneration," 
method  of,  92 

Summer  warmth,  relaxing  ef- 
fects of,  181 

Superficial  sensibility,  93 

Superior  cerebellar  commis- 
sure, fibres  of,  58 

Superior  cerebellar  peduncle, 
paths  of,  61 

Superior  colliculi,  fibres  to,  70 

Superior  colliculi  of  the  quad- 
rigemina,  connections 
of,  51,  52 

Superior  medullary  velum,  27, 
59 

Superior  olivary  nucleus,  14 
connections  of  the,  56-58 
fibres  from,  52,  53 

Superior  olive,  fibres  to  the, 
41 


Superior  orbital  fissure,  27 

Superior     peduncle,     efferent 
cerebellar  tracts  through 
the,  96 
paths  through  the,  95 
section  of,  313 

Superior  vestibular  nucleus,  18 

Suprasegmental  tracts,  mean- 
ing of,  90 

Sustentacular  cells,  descrip- 
tion of,  9 

Swing,  experiments  with,  278 

Swings,  effect  of,  upon  rota- 
tion subjects,  192 

Sylvius,   aqueduct   of,  22,  23, 
24,    29,    48,    50,    66,   69, 
178 
grey  matter  of,  69 

Sympathectomy,  general  ef- 
fect of,  109 

Sympathetic  autonomics,  32 

Sympathetic  ganglionectomy, 
110 

Sympathetic  nervous  system, 
preganglionic  fibres  of, 
90,  99 

Sympathetic  or  autonomic 
nervous  system,  98-104 

Sympathetic  reflexes  in  the 
normal  individual,  99 

Sympathetic  system,  normal 
mode  of  stimulation  of, 
103 

Synkineses,  25 

Synopsis  of  anatomical  con- 
nections, 40-77 

Tactile     sensation,     pathway 

for,  82 
Taenia  semicircularis,  75 
Tangoceptive  receptors,  121 
Taste,  loss  of,  30 
sensations  of,  30 
sense  of,  32 
Taste  buds  of  tongue,  cells  of, 

84 
Taste    fibres    of    the    chorda 

tympani,  30 
Technical   terms,   explanation 

of  some  confusing,  117 
Tecto-bulbar  tracts,  fibres  of, 

51 


556 


INDEX 


Tecto-spinal  tract,  51 

fibres  of,  86 
Tegmentum  of  the  pons,  arcu- 
ate fibres  of  the,  40 
Telencephalon,       constituents 

of,  69 
Temperature,  paths  for  sensa- 
tion of,  83 
Temperature   of    the    human 
skin,  and  thermic  reac- 
tions, 207 
Temporo  -  occipito  -  cerebellar 
tract,  constituents  of,  59 
Tenth  nerve,  cell  bodies  of,  33 
efferent  fibres  of,  34 
motor  fibres  of,  34 
Test  meals,  nature  of,  235 

with  rotations,  164 
Thalamus,  fibres  to  the,  70 
ventral  surface  of,  62 
Thalamo-cortical  tracts,  75 
Thalamo-mammillary  tract,  fi- 
bres of,  65 
Third  nerve,  fibres  of,  107 

nucleus  of,  22 
Third    nucleus,    grouping    of 
nerve-cells  of,  23,  24 
region  of,  38 

relations  of,   to  the  sev- 
enth, 26 
connections  of,  25 
Thomas,  fibres  of  tract  of,  89 
Tobacco-smoke,    nausea  exci- 
ted by  odour  of,  138 
Tongue,  anterior  two-thirds  of, 
and  the  sense  of  taste,  30 
intrinsic  muscles  of,  85 
muscles  of  the,  35 
taste  buds  of,  84 
Tonic  reflexes  of  posture,  122 
Touch  cells,  nerve  fibres   of 

84 
Tonus  innervation,  278 
Toxemia  of  the  cerebral  cen- 
tres, 332 
Tract,  a  physiological  term,  79 
Tractus  cerebellaris  acusticus, 

42 
Tractus  spiralis  foraminosus, 

13 
Tractus    strio-thalamicus,    fi- 
bres of,  60,  63 


Tractus  vestibulo-spinalis   of 

Monakow,  42 
Trigonum  habenulae,  65 
Tuber  cinereum,  69 

grey  matter  of,  71 
Tuberculum  acusticum,  14 

cells  of,  15 
Twelfth    nerve   (hypoglossal) 
supplying  muscles  of  the 
tongue,  35 
Tympanum,  herpes  zoster  of 
the,  30 
inflammatory    exudations 
in  the,  246 

Uncinate   fasciculus,   connec- 
tion of,  74 
Unilateral  irrigation,  276 
Utricle,  divisions  of,  6 
macula  acustica  of,  7 
structure  of,  9 
Utriculus    proprius,    division 
of,  6 

Vago-splanchnic  section,  169 
Vagus,    preganglionic     fibres 
of,  101 
or  pneumogastricus,  33 
secretory  fibres  contained 

in,  171 
stimulation  of  the  gastric 
branches  of,  170 
Vagus  centre,  effect  of  irrita- 
tion of,  167 
Vagus   centres,  irritation  of, 

from  rotations,  170 
Vagus  irritation,  initial  effect 

of,  172 
Vagus   stimulation,    by    rota- 
tion, effects  of,  135 
effects  of  central,  135 
through  central  stump,  165 
Vascular  changes,  alternating, 

260 
Vaso-constrictor  fibres,  distri- 
bution of,  103 
Vaso-dilator    fibres,  distribu- 
tion of,  103 
for  salivary  glands,  31 
Vaso-motor    changes,    extent 
of,  113 


INDEX 


557 


Vaso-motor  mechanisms,  tonic 
effects  of  cold  upon,  181 
Vater-Pacini  corpuscles,  84 
Ventral  cochlear  nucleus,  14 
extent  and  constitution  of, 
17 
Ventral  horn,  grouping  of  cells 

in,  93 
Ventral   marginal   fasciculus, 

41,  44 
Ventral  spino-cerebellar  tract, 

cells  of,  81 
Ventral  stalk,  fibres  of,  64 
Ventral  zones,  of  metencepha- 

lon,  48 
Vermiform  process,  irritation 

of  the  upper,  289 
Vermis,  electrical  stimulation 
of  the  upper,  289 
vestibular  root-fibres  to,  57 
Vertical  nystagmus,  204,  244, 
266,   267,   276,   282,   300. 
321 
Vertigo,    extemalization    of, 
199 
from  sudden  stooping,  38 
Vestibular  apparatus,  afferent 
paths  of  the,  298 
crossed  relation  of,  309 
Vestibular     connections,    dis- 
cussion on,  48 
Vestibular  nerve,  connections 
of  the,  40-43 
division  of,  13 
entrance  of  the,   through 

the  macula  cribrosa,  5 
fibres  of,  43 

indirect    connection    with 
parts  of  the  vestibular 
nucleus,  18 
in  fishes,  20,  71 
phenomena     that     follow 

section  of,  285 
section  of,  42 
Vestibular     nucleus,    crossed 
and     uncrossed     fibres 
from,  48 


Vestibular  portion  of  eighth 

nerve,  fibres  of  the,  17 
Vestibularis,  section    of  the, 

309 
Vestibulo-olivary  tract,  42 
Vestibulo-spinal   tract,   fibres 

of,  20 
Vicq  d'Azyr,  bundle  of,  68,  72 
Vieussens,  annulus  of,  102,  108 
Violent  nystagmus,    in   aural 
irrigations  under  hypno- 
sis, 215 
Visible  nystagmus,  332 
Vision,  disturbances  of,  on  sud- 
den stooping,  38,  39 
distant,   fixation   for   and 

pupil  dilatation,  252 
near,  fixation  for  and  pupil 
contraction,  252,  255 
Visual  acts  and  conceptualiza- 
tion, 78 
Visual  fibres,  in  animals,  69 

in  man,  70 
Visual  organs   of   lower  ani- 
mals, 71 
representation  in  the  oc- 
cipital cortex,  71 
Vomiting   and   nausea,   inter- 
pretation of  phenomena 
of,  177 
Vomiting,   bye-results  of,  134 
Vomiting  mechanism,  otolithic 
apparatus  related  to,  179 

Waking  hypnosis,  184,  213 
Walking,  after  irrigations,  244 
Wasting  diseases,  nystagmus 

and  vertigo  in,  39 
Word-sounds,  loss  of  memory 

of,  78 
Worm,  connections  of  the,  58, 

59 
Writing  centre,   existence  of 

motor,  78 

Zone  of  Lissauer,  constituents 
of,  80 


INDEX    OF   AUTHORS    REFERRED    TO 
IN    THE    SEMICIRCULAR    CANALS 


Adamiik,  109 

Alexander,  246 

Anderson,   105,   106,  107,   109, 

110,  111,  113,  258,  259 
Apolant,  107 
Argyll-Robertson,  106 
Auer,  168,  169 
Auerbach,  165,  174 

Bach,  106 

Baginsky,  125 

Bailey,  90 

Balogh.  Ill 

Balthazard,  173 

Bannister,  125 

Barany,  125 

Bayliss,  98,  103,  166,  171,  186 

Beard,  184,  261 

V.  Bechterew,  15,  24,  26,  43, 
44,  45,  46,  47,  50,  51,  56,  57, 
60,   67,  70,  95,  96,  105,  106, 

111,  117,  125,  127,  259,  260, 
298,  306,  308,  309,  310,  314, 
321 

Beevor,  77,  295,  313,  315,  327, 

331 
Bernard,  111 
Bernheimer,  106 
Biehl.  125,  127,  285,  291,  306 

319,  324 
Bogroff,  106 
Braunstein,  111 
Breuer,  125,  128,  265,  273 
Brown,  25,  78 
Brown-Sequard,  125 
Briibaker,  166 
Bruce,  19,  43 
Bruck,  125 
Brunton,  34 
Budge,  105,  108,  167 


Bumm,  107 
Burdach,  79 
Burton-Opitz,  34,  101,  170 

Cajal,  79,  119 

Campbell,  31 

Campos,  109 

Cannon,  167,  169,  173,  180 

Charpy,  5 

Chauveau,  111 

Clarke,  11,  34 

Collins,  107,  113 

Comus,  257 

Crile,  134 

Crum-Brown,  125,  128 

Cunningham,  42 

Cushing,  30 

Cyon,  102 

Darkschewitsch,  106 

Darwin,  125 

De  Cyon,   102,    125,   126,  128, 

286 
Deiters,  42,  298 
Dejerine,  60,  73,  74 
Delage,  125 
Demtschenko,  109 
Dogiel,  109 
Doyon,  256 
Dreyfus,  125 
Dufour,  257 
Duval,  25,  40,  288,  297 

Edinger,  42,  49,  60,  62,  66,  68, 

73,  74 
Edkins,  171,  186 
Engelmann,  125 
Erl  anger,  94 
Ewald,  116,  125,  128,  265,  267, 

273,  286 


658 


INDEX 


559 


Ferrier,  15,  19,  25,  31,  40,  42, 
45,  97,  106,  111.  112,  113, 
114,  115,  116,  117,  167,  194, 
260,  286,  289,  292,  293,  294, 
302,  310,  313,  315,  317,  319, 
320,  326,  327,  336 

Flechsig,  77,  106 

Flourens,  105,  125,  127 

Forel,  67 

Frangois-Franck,  109,  112,  113 

Fuchs,  195,  203,  263 

Fuss,  109 

Gaskell,  35 
Goll,  79 

Goltz,  103,  125,  127,  128 
Gordinier,  40,  81,  95 
Gowers,  83,  95 
Gratiolet,  319,  324 
Grunert,  109 
Grutzner.  234 
Gudden,  114 

Haab,  111 

Haberman,  246 

Head,  31,  93 

Heese,  109 

Heine,  256 

Henderson,  134 

Henschen,  105 

Hensen,  23,  110 

Hess,  256 

Hitzig,  111,  125 

Hoche,  46,  82,  83 

Hogyes,  125,  286 

Horsley,  77,  295,  313,  315,  327, 

331 
Howell,  92,  103,  108 
Hunt,  30 

Jackson,  125 
James,  125 
Jegerow,  107 
Jessop,  258 

Kahler,  24,  285 
Katschew,  109 
Klemoff,  42 
Knoll,  106 
Koenig,  125 

Kolliker,  40,  42,  43.  55,  69,  82, 
96,  178 


Koryani,  125 
Kreidl,  125 
Kyle.  39 

Laborde.  25.  40,  125,  288,  297 
Lafarge,  313 

Langendorff,  107,  109,  110 
Langley,  31,  90,  94,  98,  99,  105, 

107,  109,  110,  113,  169 
Laslett.  80,  91 
Lee,  125.  286 
V.  Lenhossek,  69 
Lermoyez,  212 
Leven.  319,  324 
Levinsohn,  107,  109 
Lewandowski.  110 
Lodato,  109 
Loeb,  21,  71,  125 
Longet,  309,  313 
Lucae,  125 
Luciani,    115,    309,    317,    320, 

324,  326,  329 
Ludwig,  102 
Lussana,  309,  313 

Mach,  125,  128 

Magendie,  314,  319,  324 

Marchi.  97 

Marina.  107 

Maunoir.  108 

May.  169 

Meissner.  165,  174 

Meltzer,  169 

Mercier,  317 

V.  Monakow,  62.  91 

Morat,  169,  256 

Morris,  41,  42 

Mott,  46,  81,  83,  115,  315 

Munk,  25,  315 

Murphy,  169 

Neumann,  125 
Nissl,  62 

Obersteiner,  66,  68 
Ollivier,  319 
Onuf,  107,  113 
Oppenheim,  78 
Osier,  334 

Panse,  310 

Parfour  du  Petit,  109 


560 


INDEX 


Parsons,  21.  70.  71,   106,  108, 

111,  112,  113,  257 
Pawlow,  171 
Perlia,  24,  285 
Peterson,  334 
Pick,  24,  285 
Piersol,  11 
Pitres,  113 

Poirier,  5  * 

Politzer,  212 
Porter,  134 

Quain,  23 

Reid,  Waymouth,  173,  258 

Renzi,  320 

Retzius   11   22 

Risien-Russell,  40,  97,  115,  300, 
303,  309,  315.  317,  319,  320, 
321,  324,  326,  327,  329,  330, 
332 

Rivers,  93 

Rockwell,  261 

Rohmen,  257 

Rolando,  314 

Roosa,  261 

Rosenberg-,  109 

Ross,  34 

Rossolimo,  83 

Roux,  173 

Ruge,  106 

Russell,  83.  317,  318 

Rutherford,  170 

Sabin,  18 
Sacki,  106 
Salkowski,  105 
Salvioli,  173 
Sappey,  5,  69 
Saucerotte,  319 
Scarpa,  125 

Schafer,  25,  40,  49,  78.  113, 
115,  288,  298,  302,  315,  316 


Schenk.  109 

Schiff,  108,  309 

Schmaus,  106 

Schwartze,  125,  286 

Selenkowski,  109 

Sewall,  125 

Shaeffer,  106 

Shambaug-h,  37 

Sherrington,   80,   91,    92,    110, 

112,  118,  119,  120,  121,   122. 

259.  294,  295,  296.   300,  308, 

315.  316,  318,  331 
Siebenmann,  37 
Sinitzen,  109 
Solder,  82 
Spamer,  125 

Starling,  103,  166,  171,  172,  186 
Starr,  24,  114,  285   333 
von  Stein,  125 
Steiner,  125 
Sylvius,  66,  69,  178 

Techlenberg,  173 
Terrien.  257 
Tsuchida,  24,  25,  285      * 
Turner,  19,  40,  42,  97,  106 

Valentine,  167 
Van  Gehucten,  34 
Van  Giesen,  41 
Verworn,  11 
Vieussens,  102,  108 
Volckers,  23,  110 
Vulpian,  125 

Waller,  105 
Wanner,  125 
Warner,  317 
Weber,  110 

Weir-Mitchell,  117,  320 
Witmaack,  37 
Wolferz,  109 
Wolff,  106 


INDEX    TO    SEASICKNESS 


Abdominal  blood,  flow  of, 
toward  the  heart  in 
vomiting,  389 

Abdominal  organs,  concussion 
of  the,  as  a  cause  of 
seasickness,  494 

Abdominal  viscera,  effects  of 
protracted  congestion 
of,  in  seasickness,  515 

Absorption  test,  348,  349,  351, 
352,  365,  367 

Absorption  and  motility  tests, 
347 

Adaptation  of  the  functional 
activities,  the  principle 
of,  382 

Adrenalin,  action  of,  494 

Afferent  arcs,  interference 
with,  497 

Alcohol,   action  of,  upon   the 
cardio-vascular  mechan- 
ism, 358 
effect  of,  upon  the  heart- 
structure,  359 
effects  of,  upon  the  circu- 
lation, 358 
relation  of,  to  seasickness, 
510 

Amenorrhoea  following  sea- 
sickness, 513,  515 

Ampullary    receptors,    active 
stimulation  of,  364 
affected  in  mild  forms  of 
seasickness,  499 

Analyses  of  specimens  taken 
from  seasick  subjects, 
342,  343,  350,  351,  353, 
354,  360,  361,  366-368, 
370,  371,  373-375,  377, 
378,  380,  386,  387,  390- 
392,  394-396,  399,  400, 
402,  403,  405,  406,  408, 
409,  411-413,  415,  416 


Angler,  steamship,  observa- 
tions of  seasick  sub- 
jects on,  341,  343,  384, 
385,  386,  387,  390-416, 
421-430 

Arteries,  contraction  of,  in 
seasickness,  344 

Astoria,  steamship,  observa- 
tions of  seasick  subjects 
on,  346 

Athletes,    condition  of,    after 
sea  voyage,  509,  510 
"warming  up"  of,  363 

Atropin,  effect  of,  on  the  car- 
diac vagus  terminals, 
391,  408 
especially  valuable  in  com- 
bination with  strychnin, 
378,  384,  420 
value  of,  in  warding  off 
disagreeable  effects  of 
seasickness,  376,  420 

Aural  irrigations,  rotations, 
and  galvanism,  insensi- 
tiveness  to,  385 

Balancing  movements,  well 
executed  after  strych- 
nin and  atropin  at  sea, 
372 

Barker's  theory  of  seasick- 
ness, 479 

Bamett's  theory  of  seasick- 
ness, 484 

Basche's  sphygmomanometer, 
482 

Beard's  theory  of  seasickness, 
480 

Berard's  theory  of  seasick- 
ness, 479 

Binz's  theory  of  seasickness, 
482 


561 


562 


INDEX 


Books  from  ship's  library, 
danger  of  infection 
from,  517 

Broth,  ordinary,  efficient  in 
seasickness,  420 

Cabin,   bad  effects  of   a  hot, 
stuffy,  382 
ventilation   and   tempera- 
ture of  the,  in  seasick- 
ness, 418 

Caledonia,  steamship,  obser- 
vations of  seasick  sub- 
jects on,  345-347,  432-453 

Cardio-vascular  mechanism, 
action  of  alcohol  upon, 
358,  359 

Carsickness,   labyrinthine  de- 
fects in,  492 
the  result  of  fear,  492 

Cascara  sagrada  in  seasick- 
ness, 348 

Castalet,  D'Ailhaud,  theory  of 
seasickness,  480 

Cato  the  Elder  on  seasickness, 
478 

Cerebellar  exhaustion  in  sea- 
sickness, 506 

Cerebellum,  exhausting  effect 
of  interference  with,  504 

Chapman's  theory  of  seasick- 
ness, 479 

Children  immune  from  sea- 
sickness, 508 

Circulation,  changes  in,  at  sea, 
340 
disturbances  of,  as  cause 

of  seasickness,  493 
effect  on,  while  travelling 

on  a  moving  train,  365 
slow    recovery    of,     after 
seasickness,  357 

Circulatory  mechanism,  neces- 
sity for  study  of,  in  hy- 
drotherapy, 383 

Circulatory  and  gastric  dis- 
turbances in  seasick- 
ness, 487 

Cocain,  use  of,  contraindi- 
cated,  519 

Cold  air,  good  effect  of,  on  the 
circulation,  381 


Cold  bathing,  418 

effects   of,    on    the  vaso- 
motor  mechanism,   352, 
355 
tonic  hyperemia  after,  383 

Colds  at  sea,  516 

Communicable  disease,  danger 
of,  in  crowded  cabins, 
516 

Concussion,  gross,  not  the 
cause  of  seasickness,  493 

Constipation,  relief  of,  522 

Convalescents,  fallacy  of  send- 
ing them  to  sea,  512 

Cornelius's  theory  of  seasick- 
ness, 482 

Coming's  treatment  of  sea- 
sickness, 483 

Cygne,  steamship,  observa- 
tions of  seasick  subjects 
on,  367,  368 

Dancer,  a  professional,  a  vic- 
tim of  seasickness,  489 

Darnall's  theory  of  seasick- 
ness, 481 

Darwin,  Erasmus,  theory  of 
seasickness  by,  478 

Deaf-mutes,   immunity  of,  to 
galvanism,  487 
immunity  of,   to   rotation 
sickness,  503 

Deaf  persons  immune  from 
seasickness,  502 

DeVries's  theory  of  seasick- 
ness, 481 

Digestion,  phenomena  of  dis- 
turbed, 350 

Digestive  disturbances  in  sea- 
sickness, 344,  417,  418, 
494 

Disordered  circulation,  a  sec- 
ondary source  of  irrita- 
tion in  seasickness,  522 

Dolor  cerebri,  indescribable 
sickening  feeling,  360, 
377,  388,  401 

English  Channel,  its  reputa- 
tion for  causing  seasick- 
ness, 36? 


INDEX 


563 


Equilibrium,  reflex  disturb- 
ances of,  497 

Etiology  of  seasickness,  486- 
507 

Ewald  test  meals,  343-414 

Eye,  a  factor  in  equilibration, 
an  important  source  of 
afferent  impulses,  490 

Eye  disturbances,  as  a  cause 
of  seasickness,  491 

Eyes,  motions  of  the,  a  possi- 
ble cause  of  seasickness, 
505,  506 
motor  mechanisms  of  the, 

491 
relation  of  the,  to  the  op- 
tic thalamus,  507 

Features  of  seasickness,  com- 
mon, 347 

Fehling's  solution  as  a  test, 
for  sugar,  etc.,  352 

Flasschoen's  theory  of  sea- 
sickness, 484 

Gaertner's  tonometer,  482 

Gastric  contents,  analysis  of, 
351,  etc.     See  Analyses. 

Gastric  function,  failure  and 
perversion  of,  504 

Gastric  juice,  enhancing  the 
flow  of,  421 

Gastric  mucous  membrane,  de- 
coctions of,  an  aid  to  ab- 
sorption, 421 

Gastric  secretin  inert  in  sea- 
sickness, 420 

Gastric  secretion,  failure  of 
normal,  406,  407 

Gastric  and  circulatory  dis- 
turbances in  seasick- 
ness, 344 

Gastro-intestinal  motility, 
stimulation  of,  by  atro- 
pin,  399 

Guien's  theory  of  seasickness, 
479 

Guillabert's  theory  of  seasick- 
ness, 479 

gyroscope,  principle  of,  sug- 
g  e  s  t  e  d  in  preventing 
seasickness,  520,  524 


Hagen-Torn's  theory  of  sea- 
sickness, 483 

Hazen's  theory  of  seasickness, 
481 

Heart,  strain  on  the,  in  sea- 
sickness, 512 

Hints  to  seagoing  travellers, 
519 

Hippocrates's  allusion  to  sea- 
sickness, 478 

History  and  literature  of  sea- 
sickness, 478-485 

Homatropin,  instillation  of, 
384,  385,  403 

Horizontal  nystagmus,  cause 
of,  497 

Hormones,  a  decided  help  in 
treating  severe  seasick- 
ness, 522 

Hospital  facilities  on  board 
ship  generally  poor,  515 

Hot  weather,  effect  of,  on  sea- 
sickness, 488 

Hydrotherapy,  cold  procedures 
in,  and  the  circulatory 
mechanisms,  383 

Hypnotic  suggestion,  as  a  pre- 
ventative ofseasick- 
ness,  520 
effect  of,  on  subject  "F," 

409 
not  an  efficient  means  of 
preventing  seasickness, 
420 

Hypnotism,  limited  field  of 
usefulness  in  seasick- 
ness, 520 

Imagination,  influence  of,  in 
the  etiology  of  seasick- 
ness, 347 

Immunes  from  seasickness, 
509 

Intermediate  extract,  407,  420 

Invalids  being  sent  to  sea,  the 
fallacy  of,  512 

Irritation,  testing  prolonged 
effects  of  mild,  in  sea- 
sickness, 345 

Jendrassik's  reinforcement, 
404 


564 


INDEX 


Jobert's  theory  of  seasickness, 
479 

K  I  absorption  tests,  342^09 

Kinaesthetic  sense,  explana- 
tion of  term,  506 

Klein's  theory  of  seasickness, 
481 

Koepke's  theory  of  seasick- 
ness, 483 

Kramer's  theory  of  seasick- 
ness, 480 

Kreidl's  onychoscope,  482 

Labyrinth,  concussion  of  mech- 
anisms of  the,  in  boxing, 
493 

Labyrinthine  receptors,  vary- 
ing sensitiveness  of,  356 

Lady  Wolseley,  steamship,  ob- 
servations on  seasick 
subjects  on,  417,  456-461 

Literature  of  seasickness,  478- 
485 

Localization  theory.of  seasick- 
ness, the,  485 

Lorna  Doone,  steamship,  ob- 
servations on  seasick 
subjects  on,  378 

Lump-sensation  in  stomach  in 
seasick  patients,  340-401 

Maggie,  motor  launch,  obser- 
vations on  subjects  for 
seasickness  on  board  of, 
343,  430,  431 

Maillet's  theory  of  seasick- 
ness, 485 

Medical  colleges  should  give 
special  instruction  for 
treating  seasickness,  515 

Medullary  centres,  prolonged 
constant  irritation  of, 
at  sea,  355 

Nelken's  theory  of  seasick- 
ness, 479 

Nervous  and  muscular  sys- 
tems, tension  on,  in  sea- 
sickness, 504 

Nervous  centres,  exhaustion 
of,  characteristic  of  sea- 
gickness,  419 


Nervous  manifestations  o  f 
seasickness,  340 

Nervous  system,  the  effects  of 
seasickness  upon  the, 
513 

Neurotic  type,  some  persons  of 
the,  immune  from  sea- 
sickness, 487 

Neuro-vascular  mechanism,  in- 
efficiency of,  355 
tardiness    of,    in    certain 
conditions,  362 

Nystagmus  in  seasickness, 
frequent  absence  of,  502 

Occipital  headache  in  seasick- 
ness, 349 

Ocular  functions,  disturbances 
of,  and  vertigo,  490 

Odours,  influence  of,  upon  suf- 
ferers from  seasickness, 
505 

Old  age  frequently  immune 
from  seasickness,  508 

Paraesthesiae  of  the  scalp,  a 
symptom  of  seasickness, 
349 

Pellarin's  theory  of  seasick- 
ness, 479 

Perversion  of  sensory  func- 
tion, in  seasickness,  340 

Pfanz's  theory  of  seasick- 
ness, 482 

Phenomena,  characteristic,  of 
seasickness,  344,  345 

Physicians,  grave  responsibil- 
ity of,  in  sending  pa- 
tients to  sea,  514 

Pitching  of  ship  as  a  secondary 
cause  of  seasickness,  499 

Pliny  on  seasickness,  478 

Pollard's  theory  of  seasick- 
ness, 479 

Protocols  of  observations  on 
seasick  subjects,  421-477 

Psychic  depression  and  d  i  s  - 
agreeable  sights,  419 

Psychic  factor,  the,  in  sea- 
sickness, 486,  487 

Psychic  theory  of  seasickness, 
485 


INDEX 


565 


Psychic  therapeutics,  amusing 
incident  in,  371 

Pulse,  concomitant  slowing  of, 
in  seasickness,  341 

Pulse-rate,  variation  of,  in  sea- 
sickness, 344 

Pulse-rate  and  blood-pressure, 
variations  of,  in  seasick- 
ness, 347 

Pulmonary  tuberculosis  on 
board  ship,  case  of,  516, 
517 

Quatre  Freres,  fishing  smack, 
observations  of  seasick 
subjects  on,  368,  370, 
417,  465,  466 

Recovery  from  seasickness, 
419 

Reflexes,  lethargy  of  and 
"warming  up"  of  ath- 
letes, 363 

Regnault's  theory  of  seasick- 
ness, 484 

Roesen's  theory  of  seasick- 
ness, 484 

Rolling  of  a  ship  the  least 
effective  motion  in  pro- 
ducing seasickness,  499 

Rosenbach's  theory  of  seasick- 
ness, 480 

Salicyluric  acid  in  urine,  348 

Salol  motility  tests,  342-409 

Savory's  theory  of  seasick- 
ness, 481 

Schwerdt's  theory  of  seasick- 
ness, 481 

Sea,  injudicious  travelling  on, 
512 

Seasick  patients,  effect  of  to- 
bacco-smoke on,  340 

Seasickness,  a  puzzle  to  man- 
kind, 507 
aggravated  by  bad   man- 
agement, 521 
best  time  to  study  circula- 
tion in,  360 
can    be    effectively    pre- 
vented    by    judicious 
rneasures,  518 


Seasickness,  circulatory  and 
gastric  disturbances  in, 
487 

common  features  of,  347 

conflicting  reports  as  to 
immunity,  508 

developing  a  susceptibil- 
ity for,  419 

digestive  disturbances  in, 
340 

digestive  symptoms  o  f , 
348 

during  a  transatlantic 
trip,  345-356 

effects  of,  and  their  rela- 
tion to  diseased  condi- 
tions, 512-517 

effects  of,  upon  pregnant 
women,  513 

effects  of,  upon  the  ner- 
vous system,  512 

effects  of,  upon  the  organ- 
ism, 417 

etiology  of,  486-507 
eye    disturbances    as    a 
cause  of,  491 

history  and  literature  of, 
478-485 

horrors  of,  369 

hot  weather,  effect  of,  on, 
488 

how  recovery  from,  takes 
place,  518-525 

immunity  of  animals  to, 
510,  511 

important  clue  as  to  meth- 
ods of  treatment,  347 

influence  of  imagination  in 
etiology  of,  347 

nature's  most  effective 
way  in  circulatory  de- 
pression of,  389 

nervous  manifestations  of, 
340 

not  due  primarily  to  dis- 
turbance of  circulation, 
381,  417 

on  the  occurrence  of,  508- 
511 

outlines  of  treatment  of, 
518-525 

phenomena  of,  340,  344 


566 


INDEX 


Seasickness,  predisposition  to, 
509 
prime  cause  of,  340 
ppolonged  exposure  to  con- 
ditions that  cause,  41'^ 
psychic  factor  in,  486 
recovery  from,  419 
slowing  of   the  pulse  in, 

341 
studies  in,  339-421 
subconscious  memories  of 
past  experiences  of,  347 
subjective  phenomena  of, 

360 
subjective    symptoms   of, 

342 
symptoms  of,  349 
the  true  cause  of,  495 
theories  of,  478-485 
treatment  of  an  actual  at- 
tack of,  521 
value  of  atropin  in  w^ard- 
ing-  off  disagreeable  ef- 
fects of,  376 
various  devices  employed 

to  prevent,  520 
victims  of,  419 
Self-destruction  the  result  of 
poor  medical  treatment 
in  seasickness,  514 
Semicircular    canals    affected 

in  seasickness,  502 
Sewanas'    theory   of  seasick- 
ness, 479 
Shelmerdine's  theory  of  sea- 
sickness, 483 
Ship  at  sea,  motions  of,  499 
Ship,  stops  and  starts  in  mo- 
tions of,    tend   to  bring 
on  seasickness,  500 
upward  and  downward  mo- 
tions of,  may  affect  oto- 
liths, 501 
Ship  surgeons  require  special 

training,  515 
Shock,    condition   of,    in    sea- 
sickness, 492 
the  mechanism  of,  389 
Simon's  theory  of  seasickness, 

484 
Skin,     tonic    hyperemia    of, 
355 


Somatic  theory  of  seasickness. 
485 

Southwestern,  steamship,  ob- 
servations on  seasick 
subjects  on,  371,  373- 
375,  377,  378,  462,  463, 
466,  467 

Spiral  movement,  most  effec- 
tive for  producing  sick- 
ness, 499,  501 

Stomach,  a  secondary  source 
of  irritation  in  seasick- 
ness, 521 

Stomach  tube  should  not  be 
used  in  seasickness,  522 

Subconscious  memories  of  past 
experiences  of  seasick- 
ness, 347 

Subjective  phenomena  of  sea- 
sickness, 340,  351,  353 

Suicide  at  sea,  cause  of,  513, 
514 

Sumner's  theory  of  seasick- 
ness, 481 

Susceptibility  to  seasickness, 
developing  a,  419 

Swinging  beds,  chairs,  etc.,  to 
prevent  seasickness,  520 

Symptoms  of  seasickness,  342, 
349 

Taurus,  steamship,  observa- 
tions on  seasick  subjects 
on,  339,  421 

Teutonic,  steamship,  observa- 
tions on  seasick  subjects 
on,  380,  467-477 

Theories  of  seasickness,  478- 
485 

Thoma's  theory  of  seasickness, 
484 

Tiger,  steamship,  observations 
taken  on  seasick  sub- 
jects on  board  of,  454- 
456 

Tobacco-smoke,  effect  of,  on 
seasick  patients,  340,  345 

Tousey's  theory  of  seasick- 
ness, 480 

Toxic  acoustic  neuritis,  case  of 
bilateral  deafness  causecl 
by,  503 


INDEX 


567 


Transatlantic  trip,  studies  of 
seasickness  during  a, 
345-356 

Travelling  at  sea,  improve- 
ment of  general  condi- 
tions of,  514 

Treatment  of  seasickness,  im- 
portant clue  in,  347 

Urine  diminished  during  sea- 
sickness, 516 

U-tubes,  system  of,  to  prevent 
seasickness,  524 

Van  Trostenburg's  theory  of 

seasickness,  485 
Vaso-motor  exhaustion,  result 

of,  351 
Vaso-motor  mechanism,  activ- 
ity of,  340 
lethargy  of,  362 
Vaso-motor    system,    exhaus- 
tion and  recovery  of,  354 
influence  of  cold  weather 

on  the,  348 
interesting  feature  in  the 
physiology  of  the,  362 
Vertigo,  causation  of,  506 


Vestibular  terminals,  degener- 
ation of,  489 

Vestibulo-cerebellar  balanced 
mechanisms,  disturbance 
of,  364 

Vestibulo-cerebellar  mechan- 
isms, 497 

Victims  of  seasickness  may 
become  immune,  419 

Vomiting,  nature's  most  effec- 
tive way  in  relieving 
medullary  ansemia,  389 

Vomiting  of  the  cerebellar 
type,  498 

Waugh's  theory  of  seasick- 
ness, 483 

Weitlauer's  theory  of  seasick- 
ness, 482 

Well-marked  nystagmus  in 
seasickness,  absence  of, 
502 

Wollaston's  theory  of  seasick- 
ness, 478 

Women,  smoking  on  deck  of- 
fensive to,  524 

Zingher's  theory  of  seasick- 
ness, 484 


INDEX    TO    AUTHORS    REFERRED   TO 
IN    SEASICKNESS 


Barker,  479,  516 
Barnett,  484,  486 
Bayliss,  384 
Beard,  480,  508,  520 
Berard,  479 
Berillon,  484 
Bickel,  502,  506 
Bier,  484 
Binz,  482,  483 
Bonnet,  484 

Castelet,  D'Ailhaud,  480 
Cato,  478 
Chapman,  479 
Clark,  499 
Cornelius,  482 
Corning,  483,  484 
Crile,  389 

Darnall,  481 
Darwin,  Erasmus,  478 
De  Cyon,  490 
De  Vries,  481 

Edkins,  384,  393 
Ewald,  487,  490 

Farez,  484 
Ferrier,  498 
Flasschoen,  484 
Flourens,  491,  507 
Frahm,  524 

Guien,  479 
Guillabert,  479 

Hagen-Tom,  483 
Hazen,  481 
Helmholtz,  507 
Henderson,  389 


Hippocrates,  478 
Hogyes,  487 

James,  487 
Jendrassik,  404 
Jobert,  479 

Klein,  481 
Koch,  495 
Koenig,  519 
Koepke,  483 
Kramer,  480 
Kreidl,  487 

Luciani,  504 

Maillet,  485 

Nelken,  479 

Pellarin,  479 
Pfanz,  482,  483 
Pliny,  478 
Pollard,  479 
Porter,  389 

Regnault,  484 
Roesen,  484 
Rosenbach,  480,  485,  495 

Saar,  522 

Savory,  481,  482,  486 
Schiff,  487 
Schwerdt,  481 
Sewall,  498 
Sewanas,  479 
Shelmerdine,  483 
Simon,  484 
Starling,  384 
Stevens,  490 


568 


INDEX  569 

Sumner,  481  Waugh,  483 

Weir-Mitchell,  504 

Thoma,  484  Weitlauer,  482 

Tousey,  480  Witmaack,  489,  503,  509 

Wollaston,  478 

Unger,  522 

Van  Renterghem,  484  Zingher,  484 

Van  Trostenburg,  485  Zuelzer,  522 


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